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Choose a data structure  |  Firebase

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</span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/support" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Support" track-type="globalNav" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="support"> <span class="devsite-nav-text" tooltip> Support </span> </a> </li> <li class="devsite-nav-item"> <a href="//web.archive.org/web/20210523043038/https://console.firebase.google.com/" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Go to console" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="goToConsole"> <span class="devsite-nav-text" tooltip> Go to console </span> </a> </li> </ul> </div> <div class="devsite-mobile-nav-bottom" role="navigation"> <ul class="devsite-nav-list" menu="_book"> <li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/build" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion devsite-nav-beta"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Emulator Suite</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/emulator-suite" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Connect your app and prototype</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/emulator-suite/connect_and_prototype" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/emulator-suite/connect_auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Connect to the Authentication emulator</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/emulator-suite/connect_rtdb" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Connect to the Realtime Database emulator</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/emulator-suite/connect_firestore" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Connect to the Cloud Firestore emulator</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/emulator-suite/connect_storage" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Connect to the Cloud Storage emulator</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/emulator-suite/connect_functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Connect to the Cloud Functions emulator</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/emulator-suite/install_and_configure" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Install, configure and integrate</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Authentication</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/where-to-start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Where do I start?</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Users in Firebase Projects</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>iOS</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/firebaseui" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with a pre-built UI</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/manage-users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Users</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/password-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Password Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/email-link-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Email Link Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/google-signin" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Google Sign-In</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/facebook-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Facebook Login</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/apple" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with Apple</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/twitter-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Twitter Login</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/github-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>GitHub</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/microsoft-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Microsoft</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/yahoo-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Yahoo</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/game-center" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Game Center Sign-in</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/phone-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Phone Number</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/custom-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use a Custom Auth System</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/anonymous-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Anonymous Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/single-sign-on" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Enabling cross-app authentication with shared iOS Keychain</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/account-linking" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Link Multiple Auth Providers</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/passing-state-in-email-actions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Passing State in Email Actions</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/ios/errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Handle Errors</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Android</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/firebaseui" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with a pre-built UI</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started with the Firebase SDK</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/manage-users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Users</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/password-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Password Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/email-link-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Email Link Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/google-signin" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Google Sign-In</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/facebook-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Facebook Login</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/apple" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with Apple</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/twitter-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Twitter</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/github-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>GitHub</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/microsoft-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Microsoft</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/yahoo-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Yahoo</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/play-games" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Play Games Sign-in</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/phone-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Phone Number</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/custom-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use a Custom Auth System</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/anonymous-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Anonymous Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/account-linking" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Link Multiple Auth Providers</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/android/passing-state-in-email-actions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Passing State in Email Actions</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Web</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/firebaseui" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with a pre-built UI</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/manage-users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Users</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/password-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Password Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/email-link-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Email Link Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/google-signin" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Google Sign-In</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/facebook-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Facebook Login</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/apple" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with Apple</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/twitter-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Twitter</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/github-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>GitHub</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/microsoft-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Microsoft</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/yahoo-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Yahoo</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/phone-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Phone Number</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/custom-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use a Custom Auth System</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/anonymous-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Anonymous Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/account-linking" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Link Multiple Auth Providers</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/cordova" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>OAuth Sign-In for Cordova</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/auth-state-persistence" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Auth State Persistence</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/passing-state-in-email-actions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Passing State in Email Actions</span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/web/service-worker-sessions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Service Worker Sessions</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>C++</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/cpp/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/cpp/manage-users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Users</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/cpp/password-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Password Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/cpp/google-signin" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Google Sign-in</span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/cpp/play-games" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Play Games Sign-in</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/cpp/github-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>GitHub</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/cpp/facebook-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Facebook Login</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/cpp/apple" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with Apple</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/cpp/twitter-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Twitter Login</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/cpp/microsoft-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Microsoft</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/cpp/yahoo-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Yahoo</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/cpp/phone-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Phone Number</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/cpp/custom-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use a Custom Auth System</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/cpp/anonymous-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Anonymous Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/cpp/account-linking" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Link Multiple Auth Providers</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Unity</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/unity/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/unity/manage-users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Users</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/unity/password-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Password Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/unity/google-signin" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Google Sign-in</span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/unity/play-games" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Play Games Sign-in</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/unity/github-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>GitHub Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/unity/facebook-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Facebook Login</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/unity/apple" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with Apple</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/unity/twitter-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Twitter Login</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/unity/microsoft-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Microsoft</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/unity/yahoo-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Yahoo</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/unity/phone-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Phone Number</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/unity/custom-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use a Custom Auth System</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/unity/anonymous-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Anonymous Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/unity/account-linking" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Link Multiple Auth Providers</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Admin</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/admin" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/admin/manage-users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Users</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/admin/import-users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Import Users</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/admin/create-custom-tokens" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create Custom Tokens</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/admin/verify-id-tokens" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Verify ID Tokens</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/admin/manage-sessions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage User Sessions</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/admin/manage-cookies" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Session Cookies</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/admin/custom-claims" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Control Access with Custom Claims</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/admin/email-action-links" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Generating Email Action Links</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/admin/errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Errors</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/admin/migrate-admin" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Migration Guide</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/custom-email-handler" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Customize the Email Action Handler</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/extend-with-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Extend with Cloud Functions</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/case-studies" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Case Studies</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/auth/limits" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Usage Limits</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Realtime Database</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/rtdb-vs-firestore" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Choose a Database</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>iOS</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/ios/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/ios/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/ios/read-and-write" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Read and Write Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/ios/lists-of-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Work with Lists of Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/ios/offline-capabilities" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Enable Offline Capabilities</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Android</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/android/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/android/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/android/read-and-write" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Read and Write Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/android/lists-of-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Work with Lists of Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/android/offline-capabilities" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Enable Offline Capabilities</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Web</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/web/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/web/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/web/read-and-write" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Read and Write Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/web/lists-of-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Work with Lists of Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/web/offline-capabilities" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Enable Offline Capabilities</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Admin</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/admin/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/admin/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/admin/save-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Save Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/admin/retrieve-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Retrieve Data</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>REST</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/rest/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/rest/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/rest/save-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Save Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/rest/retrieve-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Retrieve Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/rest/auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Authenticate REST Requests</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>C++</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/cpp/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/cpp/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/cpp/save-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Save Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/cpp/retrieve-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Retrieve Data</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Unity</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/unity/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/unity/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/unity/save-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Save Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/unity/retrieve-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Retrieve Data</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Security &amp; Rules</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/security" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Understand Rules</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/security/get-started" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/security/core-syntax" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Security Rules</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/security/rules-conditions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Write Conditions for Security Rules</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/security/indexing-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Index Data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/rest/app-management" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Rules via REST</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Usage and Performance</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/usage/billing" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Understand Billing</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/usage/limits" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Realtime Database Limits</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/usage/monitor-usage" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Monitor Database Usage</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/usage/monitor-performance" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Monitor Database Performance</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/usage/sharding" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Scale with Multiple Databases</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/usage/profile" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Profile Your Database</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/usage/optimize" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Optimize Database Performance</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/backups" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Automated Backups</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/extend-with-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Extend with Cloud Functions</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/database/video-series" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Video series: Firebase for SQL Developers</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Cloud Firestore</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/quickstart" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Understand Cloud Firestore</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/rtdb-vs-firestore" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Compare Cloud Firestore and Realtime Database</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/data-model" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Data model</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/manage-data/data-types" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Data types</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/client/libraries" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>SDKs and client libraries</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/query-data/index-overview" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Index types</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/locations" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Database locations</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/bundles" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Data bundles</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Add and manage data</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/manage-data/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/manage-data/add-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Add data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/manage-data/transactions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Transactions and batched writes</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/transaction-data-contention" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Data contention in transaction</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/manage-data/delete-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Delete data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/using-console" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Cloud Firestore with the Firebase Console</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/manage-data/export-import" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Export and import data</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/manage-data/move-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Move data between projects</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Read data</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/query-data/get-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get data once</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/query-data/listen" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Listen for realtime updates</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/query-data/queries" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Perform simple and compound queries</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/query-data/order-limit-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Order and limit data</span></a></li><li class="devsite-nav-item"><a 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collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Solutions</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/solutions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/solutions/aggregation" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Aggregation Queries</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/solutions/counters" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Distributed counters</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/solutions/search" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Full-text search</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/solutions/presence" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Build presence</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/solutions/role-based-access" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Secure data access for users and groups</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/solutions/delete-collections" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Delete data with a callable Cloud Function</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/solutions/schedule-export" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Schedule data exports</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/solutions/shard-timestamp" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sharded timestamps</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/solutions/geoqueries" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Geo queries</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/solutions/automate-database-create" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Automating database creation</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/solutions/index-map-field" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Reduce index costs with map fields</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/solutions/serve-bundles" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Serve bundled Firestore content from a CDN</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Usage, limits, and pricing</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/quotas" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Usage and limits</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/monitor-usage" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Monitor usage</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/pricing" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Understand Cloud Firestore billing</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/billing-example" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Example Cloud Firestore costs</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/storage-size" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Understand storage size calculations</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/best-practices" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Best practices for Cloud Firestore</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Cloud Firestore integrations</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/use-rest-api" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use the Cloud Firestore REST API</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/firestore-for-rtdb" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use Cloud Firestore and Realtime Database</span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/extend-with-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Extend with Cloud Functions</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/library-integrations" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Third-party library integrations</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>API reference</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/reference/android/com/google/firebase/firestore/package-summary" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/reference/swift/firebasefirestore/api/reference/Classes" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS — Swift</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/reference/ios/firebasefirestore/api/reference/Classes" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS — Objective-C</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/reference/js/firebase.firestore" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Web</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/reference/functions/providers_firestore_" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Cloud Functions</span></a></li><li class="devsite-nav-item"><a href="//web.archive.org/web/20210523043038/https://googleapis.dev/nodejs/firestore/latest/" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Node.js</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/reference/admin/java/reference/com/google/firebase/cloud/FirestoreClient" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Java</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/reference/admin/python/firebase_admin.firestore" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Python</span></a></li><li class="devsite-nav-item"><a href="//web.archive.org/web/20210523043038/https://godoc.org/cloud.google.com/go/firestore" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Go</span></a></li><li class="devsite-nav-item"><a href="//web.archive.org/web/20210523043038/https://googleapis.github.io/google-cloud-dotnet/docs/Google.Cloud.Firestore/" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>C#</span></a></li><li class="devsite-nav-item"><a href="//web.archive.org/web/20210523043038/https://googleapis.github.io/google-cloud-php/#/docs/cloud-firestore/latest/firestore/readme" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>PHP</span></a></li><li class="devsite-nav-item"><a href="//web.archive.org/web/20210523043038/https://googleapis.github.io/google-cloud-ruby/docs/google-cloud-firestore/latest/Google/Firestore/V1beta1" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Ruby</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/reference/rest" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>REST</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/reference/rpc" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>RPC</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Samples</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/client/samples-ios" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/client/samples-android" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/firestore/client/samples-web" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Web</span></a></li></ul></devsite-expandable-nav></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Storage</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>iOS</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/ios/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/ios/create-reference" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create a Reference</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/ios/upload-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Upload Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/ios/download-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Download Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/ios/file-metadata" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use File Metadata</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/ios/delete-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Delete Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/ios/list-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>List Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/ios/handle-errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Handle Errors</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Android</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/android/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/android/create-reference" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create a Reference</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/android/upload-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Upload Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/android/download-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Download Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/android/file-metadata" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use File Metadata</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/android/delete-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Delete Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/android/list-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>List Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/android/handle-errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Handle Errors</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Web</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/web/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/web/create-reference" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create a Reference</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/web/upload-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Upload Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/web/download-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Download Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/web/file-metadata" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use File Metadata</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/web/delete-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Delete Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/web/list-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>List Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/web/handle-errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Handle Errors</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Admin</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/admin/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>C++</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/cpp/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/cpp/create-reference" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create a Reference</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/cpp/upload-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Upload Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/cpp/download-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Download Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/cpp/file-metadata" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use File Metadata</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/cpp/delete-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Delete Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/cpp/handle-errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Handle Errors</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Unity</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/unity/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/unity/create-reference" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create a Reference</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/unity/upload-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Upload Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/unity/download-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Download Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/unity/file-metadata" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use File Metadata</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/unity/delete-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Delete Files</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/unity/handle-errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Handle Errors</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Security &amp; Rules</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/security" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Understand Security</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/security/get-started" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/security/core-syntax" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Security Rules</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/security/rules-conditions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Write Conditions for Security Rules</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/monitor-storage" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Monitor activity</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/extend-with-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Extend with Cloud Functions</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/storage/gcp-integration" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Integrate with Google Cloud</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion devsite-nav-beta"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Machine Learning</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/codelabs" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Codelabs</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Custom Models</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Use a custom model</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/use-custom-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/ios/use-custom-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/android/use-custom-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/manage-hosted-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Deploy &amp; manage custom models</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Migrate from the legacy API</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/ios/migrate-from-legacy-api" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/android/migrate-from-legacy-api" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Cloud AutoML Vision Edge</span></div></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/automl-image-labeling" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/train-image-labeler" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Train image labeling models</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Label images with your models</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/ios/label-images-with-automl" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/android/label-images-with-automl" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/train-object-detector" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Train object detection models</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Detect objects with your models</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/ios/detect-objects-with-automl" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/android/detect-objects-with-automl" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/migrate-automl-datasets" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Migrate datasets</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Use Cloud Vision APIs</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Recognize text</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/recognize-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/ios/recognize-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/android/recognize-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Label images</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/label-images" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/ios/label-images" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/android/label-images" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Recognize landmarks</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/recognize-landmarks" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/ios/recognize-landmarks" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/android/recognize-landmarks" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Deprecated Vision SDKs</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Recognize text</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/ios/recognize-text-deprecated" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/android/recognize-text-deprecated" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Label images</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/ios/label-images-deprecated" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/android/label-images-deprecated" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Recognize landmarks</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/ios/recognize-landmarks-deprecated" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/android/recognize-landmarks-deprecated" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Advanced Topics</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>A/B test two versions of a model</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/ios/ab-test-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/android/ab-test-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Prepare for Production</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Protect your Cloud credentials</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/ios/secure-api-key" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml/android/secure-api-key" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Legacy Documentation</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>ML Kit for Firebase</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Vision</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Recognize text</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/recognize-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/ios/recognize-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/android/recognize-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Detect faces</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/detect-faces" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/face-detection-concepts" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Concepts</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/ios/detect-faces" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/android/detect-faces" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Scan barcodes</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/read-barcodes" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/ios/read-barcodes" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/android/read-barcodes" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Label images</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/label-images" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/ios/label-images" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/android/label-images" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Detect and track objects</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/object-detection" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/ios/detect-objects" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/android/detect-objects" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Recognize landmarks</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/recognize-landmarks" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/ios/recognize-landmarks" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/android/recognize-landmarks" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>AutoML Vision Edge</span></div></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/automl-image-labeling" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/train-image-labeler" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Train image labeling models</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Label images with your models</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/ios/label-images-with-automl" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/android/label-images-with-automl" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/migrate-automl-datasets" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Migrate datasets</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Natural Language</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Identify the language of text</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/identify-languages" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/ios/identify-languages" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/android/identify-languages" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Translate text</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/translation" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/ios/translate-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/android/translate-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/translation-terms" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Usage guidelines</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Generate smart replies</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/generate-smart-replies" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/ios/generate-smart-replies" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/android/generate-smart-replies" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Custom Models</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Use a custom model</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/use-custom-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/ios/use-custom-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/android/use-custom-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/manage-hosted-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage hosted custom models</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Use a custom TensorFlow Lite build</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/ios/use-custom-tflite" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/android/use-custom-tflite" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Advanced Topics</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>A/B test two versions of a model</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/ios/ab-test-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/android/ab-test-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Prepare for Production</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Reduce app package size</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/android/reduce-app-size" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Protect your Cloud credentials</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/ios/secure-api-key" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/ml-kit/android/secure-api-key" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li></ul></devsite-expandable-nav></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Hosting</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/use-cases" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>What can you do with Firebase Hosting?</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/quickstart" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span></a></li><li class="devsite-nav-item devsite-nav-new"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/test-preview-deploy" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test, preview, then deploy</span><span class="devsite-nav-icon material-icons" data-icon="new" data-title="New!" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-new"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/github-integration" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Deploy via GitHub pull requests</span><span class="devsite-nav-icon material-icons" data-icon="new" data-title="New!" aria-hidden="true"></span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/multisites" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Share project resources across multiple sites</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/custom-domain" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Connect a custom domain</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/full-config" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Configure hosting behavior</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/i18n-rewrites" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Configure i18n rewrites</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/reserved-urls" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Add SDKs using reserved URLs</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Serve dynamic content and host microservices</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/serverless-overview" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use Cloud Functions for Firebase</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/cloud-run" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use Cloud Run</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/manage-cache" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage cache behavior</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/manage-hosting-resources" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage live &amp; preview channels, releases, and versions</span></a></li><li class="devsite-nav-item devsite-nav-new"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/web-request-logs-and-metrics" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Monitor web request data with Cloud Logging</span><span class="devsite-nav-icon material-icons" data-icon="new" data-title="New!" aria-hidden="true"></span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/usage-quotas-pricing" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Usage, quotas, and pricing</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/hosting/api-deploy" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Deploy using the REST API</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Cloud Functions</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/use-cases" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>What can I do with Cloud Functions?</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/get-started" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/beta-v1-diff" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Upgrade to v1.0+ from beta</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Call functions directly</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/callable" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Call functions from your app</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/http-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Call functions via HTTP requests</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/schedule-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Run functions on a schedule</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Trigger background functions</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/firestore-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Cloud Firestore triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/database-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Realtime Database triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/rc-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Remote Config triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/auth-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Authentication triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/analytics-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Analytics triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/gcp-storage-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Cloud Storage triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/pubsub-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Pub/Sub triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/test-lab-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test Lab triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Write functions</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/manage-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage deployment and runtime options</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/typescript" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Write functions in TypeScript</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/terminate-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sync, async, and promises</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/retries" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Retry asynchronous functions</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/config-env" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Environment configuration</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/organize-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Organize functions</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/handle-dependencies" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Handling dependencies</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/networking" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Optimizing networking</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/tips" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Tips &amp; tricks</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Test functions</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/local-emulator" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Run functions locally</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/unit-testing" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Unit testing functions</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/local-shell" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test functions interactively</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Monitor functions</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/writing-and-viewing-logs" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Write and view logs</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/reporting-errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Report errors</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/monitored-metrics" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>View monitored metrics</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>API Reference</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/reference/functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Firebase SDK for Cloud Functions</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/reference/functions/test" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test SDK</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/callable-reference" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Protocol specification for https.onCall</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/video-series" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Video Series: learn Cloud Functions</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/functions-and-firebase" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Cloud Functions and Firebase</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/locations" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Cloud Functions locations</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/functions/quotas" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Quotas and limits</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Security Rules</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/rules" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/rules/get-started" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Understand Security Rules</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/rules/rules-language" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Security Rules language</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/rules/rules-behavior" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>How Security Rules work</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/rules/rules-and-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Security Rules and Firebase Authentication</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Write Security Rules</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/rules/basics" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Basic Security Rules</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/rules/insecure-rules" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Avoid insecure rules</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/rules/data-validation" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Data validation</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Test Security Rules</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/rules/emulator-setup" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Set up the emulator</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/rules/unit-tests" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Build unit tests</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/rules/emulator-reports" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Generate test reports</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/rules/simulator" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Quickly validate Security Rules</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/rules/manage-deploy" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage and deploy Security Rules</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion devsite-nav-beta"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Extensions</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/extensions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Use an extension in your project</span></div></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/extensions/overview-use-extensions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/extensions/install-extensions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Install an extension</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/extensions/manage-installed-extensions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage installed extensions</span></a></li><li class="devsite-nav-item"><a href="/web/20210523043038/https://firebase.google.com/docs/extensions/permissions-granted-to-extension" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Permissions granted to an extension</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-divider devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Related products</span></div></li> <li class="devsite-nav-item"><a href="//web.archive.org/web/20210523043038/https://firebase.google.com/docs/cloud-messaging/" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Cloud Messaging</span></a></li> <li class="devsite-nav-item"><a href="//web.archive.org/web/20210523043038/https://firebase.google.com/docs/remote-config/" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Remote Config</span></a></li> </ul> <ul class="devsite-nav-list" menu="Products" aria-label="Side menu" hidden> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/products-build" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Build" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="build"> <span class="devsite-nav-text" tooltip> Build </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/products-release" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Release &amp; Monitor" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="release&amp;Monitor"> <span class="devsite-nav-text" tooltip> Release &amp; Monitor </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/products-engage" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Engage" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="engage"> <span class="devsite-nav-text" tooltip> Engage </span> </a> </li> </ul> <ul class="devsite-nav-list" menu="Docs" aria-label="Side menu" hidden> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Overview" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="overview"> <span class="devsite-nav-text" tooltip> Overview </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/guides" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Fundamentals" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="fundamentals"> <span class="devsite-nav-text" tooltip> Fundamentals </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/build" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Build" track-type="navMenu" 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Custom Events" data-label="Responsive Tab: Firestore" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="firestore"> <span class="devsite-nav-text" tooltip> Firestore </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/storage" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Storage" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="storage"> <span class="devsite-nav-text" tooltip> Storage </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/ml" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: ML" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="mL"> <span class="devsite-nav-text" tooltip> ML </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/hosting" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Hosting" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="hosting"> <span class="devsite-nav-text" tooltip> Hosting </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/functions" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Cloud Functions" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="cloudFunctions"> <span class="devsite-nav-text" tooltip> Cloud Functions </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/rules" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Security Rules" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="securityRules"> <span class="devsite-nav-text" tooltip> Security Rules </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/extensions" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Extensions" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="extensions"> <span class="devsite-nav-text" tooltip> Extensions </span> </a> </li> </ul> <ul class="devsite-nav-list" menu="Release &amp; Monitor" aria-label="Side menu" hidden> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/crashlytics" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Crashlytics" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="crashlytics"> <span class="devsite-nav-text" tooltip> Crashlytics </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/perf-mon" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Performance Monitoring" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="performanceMonitoring"> <span class="devsite-nav-text" tooltip> Performance Monitoring </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/test-lab" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Test Lab" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="testLab"> <span class="devsite-nav-text" tooltip> Test Lab </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/app-distribution" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: App Distribution" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="appDistribution"> <span class="devsite-nav-text" tooltip> App Distribution </span> </a> </li> </ul> <ul class="devsite-nav-list" menu="Engage" aria-label="Side menu" hidden> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/analytics" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Analytics" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="analytics"> <span class="devsite-nav-text" tooltip> Analytics </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/remote-config" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Remote Config" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="remoteConfig"> <span class="devsite-nav-text" tooltip> Remote Config </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/predictions" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Predictions" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="predictions"> <span class="devsite-nav-text" tooltip> Predictions </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/ab-testing" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: A/B Testing" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="a/BTesting"> <span class="devsite-nav-text" tooltip> A/B Testing </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/cloud-messaging" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Cloud Messaging" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="cloudMessaging"> <span class="devsite-nav-text" tooltip> Cloud Messaging </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/in-app-messaging" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: In-App Messaging" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="in-AppMessaging"> <span class="devsite-nav-text" tooltip> In-App Messaging </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/dynamic-links" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Dynamic Links" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="dynamicLinks"> <span class="devsite-nav-text" tooltip> Dynamic Links </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/admob" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Google AdMob" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="googleAdMob"> <span class="devsite-nav-text" tooltip> Google AdMob </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/ads" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Google Ads" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="googleAds"> <span class="devsite-nav-text" tooltip> Google Ads </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210523043038/https://firebase.google.com/docs/app-indexing" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: App Indexing" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="appIndexing"> <span class="devsite-nav-text" tooltip> App Indexing </span> </a> </li> </ul> </div> </div> </nav> </devsite-book-nav> <section id="gc-wrapper"> <main role="main" class="devsite-main-content" has-book-nav has-toc> <devsite-toc class="devsite-nav"></devsite-toc> <devsite-content> <article class="devsite-article"><style> /* Styles inlined from /styles/docs.css */ .center { text-align: center } /* Used in AdMob code examples */ .oldcode { opacity: .40; /* IE 8 */ -ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=40)"; filter: progid:DXImageTransform.Microsoft.Alpha(Opacity=40); /* IE <= 7 */ filter:alpha(opacity=40); } .newcode { font-weight: bold; } /* Device Screenshots */ .deviceshot { max-width: 700px; max-height: 400px; } /* Start Changelog styles */ .badge { position: relative; top: -3px; border-radius: 16px; display: inline-block; width: 90px; height: 32px; line-height: 32px; margin-right: 10px; text-transform: uppercase; font-size: 13px; font-weight: 700; text-align: center; } /* Colours for each type of changelog entry. */ /* TODO: Change the colours to match the site colour scheme */ .badge-changed { background-color: #F4B400; color: #fff; } .badge-fixed { background-color: #4285F4; color: #fff; } .badge-important { background-color: #DB4437; color: #fff; } .badge-feature { background-color: #0F9D58; color: #fff; } .badge-deprecated { background-color: #DB4437; color: #fff; } .badge-issue { background-color: #DB4437; color: #fff; } .changelog > ul { padding-left: 0; } .changelog > ul > li { list-style-type: none; margin-bottom: 22px; } .firebase-support-release-page .changelog > ul { list-style-type: none; padding-left: 110px; } .firebase-release-roundup .changelog > ul { list-style-type: disc outside; padding-left: 40px; } .firebase-release-roundup .changelog > ul > li { list-style-type: disc outside; margin-bottom: 12px; } .release-changed::before, .release-feature::before, .release-fixed::before, .release-issue::before, .release-deprecated::before, .release-removed::before, .release-unchanged::before, .release-rules::before, .release-android::before, .release-android-bom::before, .release-ios::before, .release-admin::before, .release-cpp::before, .release-unity::before, .release-functions::before, .release-javascript::before { display: block; float: left; color: white; width: 100px; height: 32px; margin-left: -110px; margin-right: 10px; margin-top: -5px; padding-top: 4px; text-transform: uppercase; font-size: 13px; font-weight: 700; text-align: center; border-radius: 16px; } .release-changed::before { content: "changed"; background-color: #F4B400; } .release-feature::before { content: "feature"; background-color: #0F9D58; } .release-fixed::before { content: "fixed"; background-color: #4285F4; } .release-issue::before { content: "issue"; background-color: #DB4437; } .release-deprecated::before { content: "deprecated"; background-color: #E65100; } .release-removed::before { content: "removed"; background-color: #546E7A; } .release-unchanged::before { content: "no change"; background-color: #CCCCCC; } .release-android::before { content: "android"; background-color: #A4C639; } .release-android-bom::before { content: "android bom"; background-color: #A4C639; } .release-ios::before { text-transform: none; content: "iOS"; background-color: #007aff; } .release-admin::before { content: "admin"; background-color: #039BE5; } .release-cpp::before { content: "c++"; background-color: #FF8A65; } .release-unity::before { content: "unity"; background-color: #00cccc; } .release-functions::before { content: "functions"; background-color: #2C384A; } .release-javascript::before { content: "javascript"; background-color: #7e57c2; } .release-rules::before { content: "rules"; background-color: #1B3A57; } /* End Changelog styles */ /* Docs Overview page styles */ .docs-android, .docs-ios, .docs-web, .docs-cpp, .docs-unity { height: 64px; width: 64px; margin: 10px 16px 0 -16px; } .firebase-docs-overview .devsite-landing-row h2 { margin: 80px 0 -40px; } .devsite-landing-row-3-up .docs-landing-row-item { width: calc((100% - 80px)/2); display: inline-block; } .docs-landing-icon { font-size: 48px; height: 48px; margin: 11px; width: 48px; } .firebase-reference-list { display: -ms-flex; display: flex; -ms-flex-wrap: wrap; flex-wrap: wrap; list-style: none; margin: 0 0 40px; padding: 0; } .firebase-reference-list-item { -ms-flex: 0 0 50%; flex: 0 0 50%; margin: 40px 0 0; padding: 0; } .firebase-reference-list-item > a { -ms-flex-align: center; align-items: center; display: -ms-flex; display: flex; } .firebase-reference-list-item > a:not(:hover) h3 { color: #424242; } .firebase-reference-list-item > a:not(:hover) li, .firebase-reference-list-item > a:not(:hover) p { color: #757575; } .firebase-reference-list-item .docs-landing-icon { -ms-flex-align: center; align-items: center; background-color: #f5f5f5; border-radius: 50%; -ms-flex: 0 0 88px; flex: 0 0 88px; height: 88px; -ms-justify-content: center; justify-content: center; margin: 0 16px 0 0; padding: 20px; } .firebase-reference-list-item h3 { -ms-flex: 0 0 auto; flex: 0 0 auto; font-size: 18px; line-height: 28px; margin: 0; } .firebase-reference-list-item ul { list-style: none; padding: 0; } .docs-android, .docs-ios, .docs-web, .docs-cpp, .docs-unity { height: 88px; width: auto; } .firebase-reference-list-item.docs-android .docs-landing-icon { color: #00bfa5; } .firebase-reference-list-item.docs-cpp .docs-landing-icon { color: #fd8c09; } .firebase-reference-list-item.docs-ios .docs-landing-icon { color: #16aaca; } .firebase-reference-list-item.docs-unity .docs-landing-icon { color: #000000; } .firebase-reference-list-item.docs-web .docs-landing-icon { color: #c52062; } .firebase-reference-list-item.docs-http .docs-landing-icon { color: #3F51B5; } @media (max-width: 1000px) { .firebase-reference-list { -ms-flex-direction: column; flex-direction: column; } } /* end Docs Overview page styles */ /* Full-page platform selector for Crashlytics docs */ /* Note: h3 in selector content must include hide-from-toc */ .full-page-selector, .full-page-selector-content { border: none; font-size: inherit; } 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href="https://web.archive.org/web/20210523043038/https://services.google.com/fb/forms/firebasealphaprogram/" target="_blank" rel="noopener noreferrer">alpha program</a> for early access to the new Remote Config personalization feature. <a href="https://web.archive.org/web/20210523043038/https://firebase.googleblog.com/2021/05/whats-new-from-firebase-at-google-io.html" target="_blank" rel="noopener noreferrer">Learn more</a> </div> </div> </div> <div class="devsite-article-meta nocontent" role="navigation"> <ul class="devsite-breadcrumb-list" aria-label="Breadcrumb"> <li class="devsite-breadcrumb-item "> <a href="https://web.archive.org/web/20210523043038/https://firebase.google.com/" class="devsite-breadcrumb-link gc-analytics-event" data-category="Site-Wide Custom Events" data-label="Breadcrumbs" data-value="1" track-type="globalNav" track-name="breadcrumb" track-metadata-position="1" track-metadata-eventdetail="Firebase"> Firebase </a> </li> <li class="devsite-breadcrumb-item "> <div 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track-metadata-position="thumb-rating" project-feedback-url="https://firebase.google.com/support/contact/bugs-features/" project-icon="https://firebase.google.com/_static/firebase/images/logo.png" project-support-url="https://firebase.google.com/support/" feedback-type="thumb-rating"> <button> Need to tell us more? </button> </devsite-feedback> </template> </devsite-thumb-rating> </div> <devsite-feedback position="header" project-name="Firebase" product-id="719752" bucket="" context="" version="t-devsite-webserver-20210511-r02-rc02.435214142688440520" data-label="Send Feedback Button" track-type="feedback" track-name="sendFeedbackLink" track-metadata-position="header" project-feedback-url="https://firebase.google.com/support/contact/bugs-features/" project-icon="https://firebase.google.com/_static/firebase/images/logo.png" project-support-url="https://firebase.google.com/support/" feedback-type="thumb-rating"> <button> Send feedback </button> </devsite-feedback> <h1 class="devsite-page-title">Choose a data structure</h1> <devsite-toc class="devsite-nav" devsite-toc-embedded> </devsite-toc> <div class="devsite-article-body clearfix "> <style>ul { list-style: none; }</style> <div class="video-wrapper-left"> <iframe class="devsite-embedded-youtube-video" data-video-id="haMOUb3KVSo" data-autohide="1" data-showinfo="0" frameborder="0" allowfullscreen> </iframe> </div> <div class="video-wrapper"> <iframe class="devsite-embedded-youtube-video" data-video-id="o7d5Zeic63s" data-autohide="1" data-showinfo="0" frameborder="0" allowfullscreen> </iframe> </div> <p>Remember, when you structure your data in Cloud Firestore, you have a few different options: <ul style="list-style: disc outside"> <li>Documents</li> <li>Multiple collections</li> <li>Subcollections within documents</li> </ul> <p>Consider the advantages of each option as they relate to your use case. A few example structures for hierarchical data are outlined in this guide.</p></p> <h3 id="nested_data_in_documents" data-text="Nested data in documents">Nested data in documents</h3> <p>You can nest complex objects like arrays or maps within documents.</p> <table> <tr> <td> <ul> <li><strong>Advantages:</strong> If you have simple, fixed lists of data that you want to keep within your documents, this is easy to set up and streamlines your data structure.</li> <li> <strong>Limitations:</strong> This isn't as scalable as other options, especially if your data expands over time. With larger or growing lists, the document also grows, which can lead to slower document retrieval times. </li> <li><strong>What's a possible use case?</strong> In a chat app, for example, you might store a user's 3 most recently visited chat rooms as a nested list in their profile. </li> </ul> </td> <td style="width:35%"> <ul><li> <span class="material-icons notranslate" aria-hidden="true" translate="no">class</span> alovelace<br/> <ul><li>&nbsp;&nbsp;&nbsp;&nbsp;name :<br/> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;first : "Ada"<br/> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;last : "Lovelace"<br/> &nbsp;&nbsp;&nbsp;&nbsp;born : 1815<br/> &nbsp;&nbsp;&nbsp;&nbsp;rooms :<br/> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0 : "Software Chat"<br/> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1 : "Famous Figures"<br/> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2 : "Famous SWEs"<br/> </li> </ul> </li> </ul> </td> </tr> </table> <h3 id="subcollections" data-text="Subcollections">Subcollections</h3> <p>You can create collections within documents when you have data that might expand over time.</p> <table> <tr> <td> <ul> <li><strong>Advantages:</strong> As your lists grow, the size of the parent document doesn't change. You also get full query capabilities on subcollections, and you can issue <a href="https://web.archive.org/web/20210523043038/https://firebase.google.com/docs/firestore/query-data/queries"> collection group queries</a> across subcollections. </li> <li> <strong>Limitations:</strong> You can't easily delete subcollections. </li> <li><strong>What's a possible use case?</strong> In the same chat app, for example, you might create collections of users or messages within chat room documents. </li> </ul> </td> <td style="width:35%"> <ul> <li><span class="material-icons notranslate" aria-hidden="true" translate="no">collections_bookmark</span> science <ul><li><span class="material-icons notranslate" aria-hidden="true" translate="no">class</span> software<br/> &nbsp;&nbsp;name : "software chat" <ul><li><span class="material-icons notranslate" aria-hidden="true" translate="no">collections_bookmark</span> users <ul><li><span class="material-icons notranslate" aria-hidden="true" translate="no">class</span> alovelace<br/> &nbsp;&nbsp;&nbsp;&nbsp;first : "Ada"<br/> &nbsp;&nbsp;&nbsp;&nbsp;last : "Lovelace"<br/> </li> <li><span class="material-icons notranslate" aria-hidden="true" translate="no">class</span> sride<br/> &nbsp;&nbsp;&nbsp;&nbsp;first : "Sally"<br/> &nbsp;&nbsp;&nbsp;&nbsp;last : "Ride"`</li> </ul> </li> </ul><br/><br/> <li><span class="material-icons notranslate" aria-hidden="true" translate="no">class</span> astrophysics <ul><li>...<br/></li></ul> </li> </li> </ul> </td> </tr> </table> <h3 id="root-level_collections" data-text="Root-level collections">Root-level collections</h3> <p>Create collections at the root level of your database to organize disparate data sets.</p> <table> <tr> <td> <ul> <li><strong>Advantages:</strong> Root-level collections are good for many-to-many relationships and provide powerful querying within each collection. </li> <li> <strong>Limitations:</strong> Getting data that is naturally hierarchical might become increasingly complex as your database grows. </li> <li><strong>What's a possible use case?</strong> In the same chat app, for example, you might create one collection for users and another for rooms and messages. </li> </ul> </td> <td style="width:35%"> <ul> <li><span class="material-icons notranslate" aria-hidden="true" translate="no">collections_bookmark</span> users <ul><li> <span class="material-icons notranslate" aria-hidden="true" translate="no">class</span> alovelace<br/> &nbsp;&nbsp;&nbsp;&nbsp;first : "Ada"<br/> &nbsp;&nbsp;&nbsp;&nbsp;last : "Lovelace"<br/> &nbsp;&nbsp;&nbsp;&nbsp;born : 1815<br/> </li> <li><span class="material-icons notranslate" aria-hidden="true" translate="no">class</span> sride<br/> &nbsp;&nbsp;&nbsp;&nbsp;first : "Sally"<br/> &nbsp;&nbsp;&nbsp;&nbsp;last : "Ride"<br/> &nbsp;&nbsp;&nbsp;&nbsp;born : 1951<br/> </li> </ul> </li> <li><span class="material-icons notranslate" aria-hidden="true" translate="no">collections_bookmark</span> rooms <ul><li><span class="material-icons notranslate" aria-hidden="true" translate="no">class</span> software <ul><li><span class="material-icons notranslate" aria-hidden="true" translate="no">collections_bookmark</span> messages <ul><li><span class="material-icons notranslate" aria-hidden="true" translate="no">class</span> message1<br/> &nbsp;&nbsp;&nbsp;&nbsp;from : "alovelace"<br/> &nbsp;&nbsp;&nbsp;&nbsp;content : "..."<br/> </li> <li><span class="material-icons notranslate" aria-hidden="true" translate="no">class</span> message2<br/> &nbsp;&nbsp;&nbsp;&nbsp;from : "sride"<br/> &nbsp;&nbsp;&nbsp;&nbsp;content : "..."<br/> </li> </ul> </li> </ul> </li> </ul> </li> </ul> </td> </tr> </table> </div> <devsite-thumb-rating position="footer"> <template class="thumb-down-categories"> [{ "type": "thumb-down", "id": "missingTheInformationINeed", "label":"Missing the information I need" },{ "type": "thumb-down", "id": "tooComplicatedTooManySteps", "label":"Too complicated / too many steps" },{ "type": 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