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href="/libraries/dart-convert"><div><span>dart:convert</span></div></a></li><li class="nav-item"><a class="nav-link" href="/libraries/dart-io"><div><span>dart:io</span></div></a></li><li class="nav-item"><a class="nav-link" href="/interop/js-interop"><div><span>dart:js_interop</span></div></a></li><div class="sidenav-divider"></div><li class="nav-item"><a class="nav-link" href="/libraries/collections/iterables"><div><span>Iterable collections</span></div></a></li><li class="nav-item"><button class="nav-link collapsible collapsed" data-toggle="collapse" data-target="#-sidenav-2-10" role="button" aria-expanded="false" aria-controls="-sidenav-2-10"><span>Asynchronous programming</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-2-10"><li class="nav-item"><a class="nav-link" href="/libraries/async/async-await"><div><span>Tutorial</span></div></a></li><li class="nav-item"><a class="nav-link" href="/libraries/async/futures-error-handling"><div><span>Futures and error handling</span></div></a></li><li class="nav-item"><a class="nav-link" href="/libraries/async/using-streams"><div><span>Using streams</span></div></a></li><li class="nav-item"><a class="nav-link" href="/libraries/async/creating-streams"><div><span>Creating streams</span></div></a></li></ul></li></ul></li><li class="nav-item"><button class="nav-link collapsed collapsible" data-toggle="collapse" data-target="#-sidenav-3" role="button" aria-expanded="false" aria-controls="-sidenav-3"><span>Effective Dart</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-3"><li class="nav-item"><a class="nav-link" href="/effective-dart"><div><span>Overview</span></div></a></li><li class="nav-item"><a class="nav-link" href="/effective-dart/style"><div><span>Style</span></div></a></li><li class="nav-item"><a class="nav-link" href="/effective-dart/documentation"><div><span>Documentation</span></div></a></li><li class="nav-item"><a class="nav-link" href="/effective-dart/usage"><div><span>Usage</span></div></a></li><li class="nav-item"><a class="nav-link" href="/effective-dart/design"><div><span>Design</span></div></a></li></ul></li><li class="nav-item"><button class="nav-link collapsed collapsible" data-toggle="collapse" data-target="#-sidenav-4" role="button" aria-expanded="false" aria-controls="-sidenav-4"><span>Packages</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-4"><li class="nav-item"><a class="nav-link" href="/tools/pub/packages"><div><span>How to use packages</span></div></a></li><li class="nav-item"><a class="nav-link" href="/resources/useful-packages"><div><span>Commonly used packages</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/pub/create-packages"><div><span>Creating packages</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/pub/publishing"><div><span>Publishing packages</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/pub/writing-package-pages"><div><span>Writing package pages</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/pub/workspaces"><div><span>Workspaces (monorepo support)</span></div></a></li><li class="nav-item"><button class="nav-link collapsible collapsed" data-toggle="collapse" data-target="#-sidenav-4-7" role="button" aria-expanded="false" aria-controls="-sidenav-4-7"><span>Package reference</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-4-7"><li class="nav-item"><a class="nav-link" href="/tools/pub/dependencies"><div><span>Dependencies</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/pub/glossary"><div><span>Glossary</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/pub/package-layout"><div><span>Package layout conventions</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/pub/environment-variables"><div><span>Pub environment variables</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/pub/pubspec"><div><span>Pubspec file</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/pub/troubleshoot"><div><span>Troubleshooting pub</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/pub/verified-publishers"><div><span>Verified publishers</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/pub/security-advisories"><div><span>Security advisories</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/pub/versioning"><div><span>Versioning</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/pub/custom-package-repositories"><div><span>Custom package repositories</span></div></a></li></ul></li><li class="nav-item"><a class="nav-link" href="/tools/pub/private-files"><div><span>What not to commit</span></div></a></li></ul></li><li class="nav-item"><button class="nav-link collapsed collapsible" data-toggle="collapse" data-target="#-sidenav-5" role="button" aria-expanded="false" aria-controls="-sidenav-5"><span>Development</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-5"><li class="nav-item"><a class="nav-link" href="/libraries/serialization/json"><div><span>JSON serialization</span></div></a></li><li class="nav-item"><a class="nav-link" href="/resources/language/number-representation"><div><span>Number representation</span></div></a></li><li class="nav-item"><a class="nav-link" href="/resources/google-apis"><div><span>Google APIs</span></div></a></li><li class="nav-item"><a class="nav-link" href="/multiplatform-apps"><div><span>Multi-platform apps</span></div></a></li><li class="nav-item"><button class="nav-link collapsible collapsed" data-toggle="collapse" data-target="#-sidenav-5-5" role="button" aria-expanded="false" aria-controls="-sidenav-5-5"><span>Command-line & server apps</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-5-5"><li class="nav-item"><a class="nav-link" href="/server"><div><span>Overview</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tutorials/server/get-started"><div><span>Get started</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tutorials/server/cmdline"><div><span>Write command-line apps</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tutorials/server/fetch-data"><div><span>Fetch data from the internet</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tutorials/server/httpserver"><div><span>Write HTTP servers</span></div></a></li><li class="nav-item"><a class="nav-link" href="/server/libraries"><div><span>Libraries & packages</span></div></a></li><li class="nav-item"><a class="nav-link" href="/server/google-cloud"><div><span>Google Cloud</span></div></a></li></ul></li><li class="nav-item"><button class="nav-link collapsible collapsed" data-toggle="collapse" data-target="#-sidenav-5-6" role="button" aria-expanded="false" aria-controls="-sidenav-5-6"><span>Web apps</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-5-6"><li class="nav-item"><a class="nav-link" href="/web"><div><span>Overview</span></div></a></li><li class="nav-item"><a class="nav-link" href="/web/get-started"><div><span>Get started</span></div></a></li><li class="nav-item"><a class="nav-link" href="/web/deployment"><div><span>Deployment</span></div></a></li><li class="nav-item"><a class="nav-link" href="/web/libraries"><div><span>Libraries & packages</span></div></a></li><li class="nav-item"><a class="nav-link" href="/web/wasm"><div><span>Wasm compilation</span></div></a></li></ul></li><li class="nav-item"><a class="nav-link" href="/libraries/core/environment-declarations"><div><span>Environment declarations</span></div></a></li></ul></li><li class="nav-item"><button class="nav-link collapsed collapsible" data-toggle="collapse" data-target="#-sidenav-6" role="button" aria-expanded="false" aria-controls="-sidenav-6"><span>Interoperability</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-6"><li class="nav-item"><a class="nav-link" href="/interop/c-interop"><div><span>C interop</span></div></a></li><li class="nav-item"><a class="nav-link" href="/interop/objective-c-interop"><div><span>Objective-C & Swift interop</span></div></a></li><li class="nav-item"><a class="nav-link" href="/interop/java-interop"><div><span>Java & Kotlin interop</span></div></a></li><li class="nav-item"><button class="nav-link collapsible collapsed" data-toggle="collapse" data-target="#-sidenav-6-4" role="button" aria-expanded="false" aria-controls="-sidenav-6-4"><span>JavaScript interop</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-6-4"><li class="nav-item"><a class="nav-link" href="/interop/js-interop"><div><span>Overview</span></div></a></li><li class="nav-item"><a class="nav-link" href="/interop/js-interop/usage"><div><span>Usage</span></div></a></li><li class="nav-item"><a class="nav-link" href="/interop/js-interop/js-types"><div><span>JS types</span></div></a></li><li class="nav-item"><a class="nav-link" href="/interop/js-interop/tutorials"><div><span>Tutorials</span></div></a></li><li class="nav-item"><a class="nav-link" href="/interop/js-interop/past-js-interop"><div><span>Past JS interop</span></div></a></li><div class="sidenav-divider"></div><li class="nav-item"><a class="nav-link" href="/interop/js-interop/package-web"><div><span>Web interop</span></div></a></li></ul></li></ul></li><li class="nav-item"><button class="nav-link collapsed collapsible" data-toggle="collapse" data-target="#-sidenav-7" role="button" aria-expanded="false" aria-controls="-sidenav-7"><span>Tools & techniques</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-7"><li class="nav-item"><a class="nav-link" href="/tools"><div><span>Overview</span></div></a></li><li class="nav-item"><button class="nav-link collapsible collapsed" data-toggle="collapse" data-target="#-sidenav-7-2" role="button" aria-expanded="false" aria-controls="-sidenav-7-2"><span>Editors & debuggers</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-7-2"><li class="nav-item"><a class="nav-link" href="/tools/jetbrains-plugin"><div><span>IntelliJ & Android Studio</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/vs-code"><div><span>VS Code</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/dart-devtools"><div><span>Dart DevTools</span></div></a></li><li class="nav-item"><button class="nav-link collapsible collapsed" data-toggle="collapse" data-target="#-sidenav-7-2-4" role="button" aria-expanded="false" aria-controls="-sidenav-7-2-4"><span>DartPad</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-7-2-4"><li class="nav-item"><a class="nav-link" href="/tools/dartpad"><div><span>Overview</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/dartpad/troubleshoot"><div><span>Troubleshooting DartPad</span></div></a></li></ul></li></ul></li><li class="nav-item"><button class="nav-link collapsible collapsed" data-toggle="collapse" data-target="#-sidenav-7-3" role="button" aria-expanded="false" aria-controls="-sidenav-7-3"><span>Command-line tools</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-7-3"><li class="nav-item"><button class="nav-link collapsible" data-toggle="collapse" data-target="#-sidenav-7-3-1" role="button" aria-expanded="true" aria-controls="-sidenav-7-3-1"><span>Dart SDK</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse show" id="-sidenav-7-3-1"><li class="nav-item"><a class="nav-link" href="/tools/sdk"><div><span>Overview</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/dart-tool"><div><span>dart</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/dart-analyze"><div><span>dart analyze</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/dart-compile"><div><span>dart compile</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/dart-create"><div><span>dart create</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/dart-doc"><div><span>dart doc</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/dart-fix"><div><span>dart fix</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/dart-format"><div><span>dart format</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/dart-info"><div><span>dart info</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/pub/cmd"><div><span>dart pub</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/dart-run"><div><span>dart run</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/dart-test"><div><span>dart test</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/dartaotruntime"><div><span>dartaotruntime</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/experiment-flags"><div><span>Experiment flags</span></div></a></li></ul></li><li class="nav-item"><button class="nav-link collapsible" data-toggle="collapse" data-target="#-sidenav-7-3-2" role="button" aria-expanded="true" aria-controls="-sidenav-7-3-2"><span>Other command-line tools</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse show" id="-sidenav-7-3-2"><li class="nav-item"><a class="nav-link" href="/tools/build_runner"><div><span>build_runner</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/webdev"><div><span>webdev</span></div></a></li></ul></li></ul></li><li class="nav-item"><button class="nav-link collapsible collapsed" data-toggle="collapse" data-target="#-sidenav-7-4" role="button" aria-expanded="false" aria-controls="-sidenav-7-4"><span>Static analysis</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-7-4"><li class="nav-item"><a class="nav-link" href="/tools/analysis"><div><span>Customizing static analysis</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/non-promotion-reasons"><div><span>Fixing type promotion failures</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/linter-rules"><div><span>Linter rules</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tools/diagnostic-messages"><div><span>Diagnostic messages</span></div></a></li></ul></li><li class="nav-item"><button class="nav-link collapsible collapsed" data-toggle="collapse" data-target="#-sidenav-7-5" role="button" aria-expanded="false" aria-controls="-sidenav-7-5"><span>Testing & optimization</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-7-5"><li class="nav-item"><a class="nav-link" href="/tools/testing"><div><span>Testing</span></div></a></li><li class="nav-item"><a class="nav-link" href="/web/debugging"><div><span>Debugging web apps</span></div></a></li></ul></li></ul></li><li aria-hidden="true"><div class="sidenav-divider"></div></li><li class="nav-item"><button class="nav-link collapsed collapsible" data-toggle="collapse" data-target="#-sidenav-9" role="button" aria-expanded="false" aria-controls="-sidenav-9"><span>Resources</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-9"><li class="nav-item"><a class="nav-link" href="/resources/dart-cheatsheet"><div><span>Language cheatsheet</span></div></a></li><li class="nav-item"><a class="nav-link" href="/resources/breaking-changes"><div><span>Breaking changes</span></div></a></li><li class="nav-item"><a class="nav-link" href="/resources/language/evolution"><div><span>Language evolution</span></div></a></li><li class="nav-item"><a class="nav-link" href="/resources/language/spec"><div><span>Language specification</span></div></a></li><li class="nav-item"><a class="nav-link" href="/resources/dart-3-migration"><div><span>Dart 3 migration guide</span></div></a></li><li class="nav-item"><button class="nav-link collapsible collapsed" data-toggle="collapse" data-target="#-sidenav-9-6" role="button" aria-expanded="false" aria-controls="-sidenav-9-6"><span>Coming from ...</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse" id="-sidenav-9-6"><li class="nav-item"><a class="nav-link" href="/resources/coming-from/js-to-dart"><div><span>JavaScript to Dart</span></div></a></li><li class="nav-item"><a class="nav-link" href="/resources/coming-from/swift-to-dart"><div><span>Swift to Dart</span></div></a></li></ul></li><div class="sidenav-divider"></div><li class="nav-item"><a class="nav-link" href="/resources/faq"><div><span>FAQ</span></div></a></li><li class="nav-item"><a class="nav-link" href="/resources/glossary"><div><span>Glossary</span></div></a></li><li class="nav-item"><a class="nav-link" href="/resources/books"><div><span>Books</span></div></a></li><li class="nav-item"><a class="nav-link" href="/resources/videos"><div><span>Videos</span></div></a></li><li class="nav-item"><a class="nav-link" href="/tutorials"><div><span>Tutorials</span></div></a></li></ul></li><li class="nav-item"><button class="nav-link collapsible" data-toggle="collapse" data-target="#-sidenav-10" role="button" aria-expanded="true" aria-controls="-sidenav-10"><span>Related sites</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse show" id="-sidenav-10"><li class="nav-item"><a class="nav-link" href="https://api.dart.dev" target="_blank" rel="noopener"><div><span>API reference</span><span class="material-symbols" aria-hidden="true">open_in_new</span></div></a></li><li class="nav-item"><a class="nav-link" href="https://medium.com/dartlang" target="_blank" rel="noopener"><div><span>Blog</span><span class="material-symbols" aria-hidden="true">open_in_new</span></div></a></li><li class="nav-item"><a class="nav-link" href="https://dartpad.dev" target="_blank" rel="noopener"><div><span>DartPad (online editor)</span><span class="material-symbols" aria-hidden="true">open_in_new</span></div></a></li><li class="nav-item"><a class="nav-link" href="https://flutter.dev" target="_blank" rel="noopener"><div><span>Flutter</span><span class="material-symbols" aria-hidden="true">open_in_new</span></div></a></li><li class="nav-item"><a class="nav-link" href="https://pub.dev" target="_blank" rel="noopener"><div><span>Package site</span><span class="material-symbols" aria-hidden="true">open_in_new</span></div></a></li></ul></li></ul></div><main id="page-content"><div id="site-toc--side" class="site-toc"><header class="site-toc__title">Contents</header><ul class="section-nav"><li class="toc-entry nav-item"><a class="nav-link" href="#library-tour">Library tour</a></li><li class="toc-entry nav-item"><a class="nav-link" href="#multi-platform-libraries">Multi-platform libraries</a></li><li class="toc-entry nav-item"><a class="nav-link" href="#native-platform-libraries">Native platform libraries</a></li><li class="toc-entry nav-item"><a class="nav-link" href="#web-platform-libraries">Web platform libraries</a></li></ul></div><article><div class="content"><div id="site-content-title"><h1>Dart's core libraries</h1></div><div id="site-toc--inline" class="site-toc"><header class="site-toc__title">Contents</header><ul class="section-nav"><li class="toc-entry"><a href="#library-tour">Library tour</a></li><li class="toc-entry"><a href="#multi-platform-libraries">Multi-platform libraries</a></li><li class="toc-entry"><a href="#native-platform-libraries">Native platform libraries</a></li><li class="toc-entry"><a href="#web-platform-libraries">Web platform libraries</a></li></ul></div><style>th:first-child { width: 80%; }</style><p>Dart has a rich set of core libraries that provide essentials for many everyday programming tasks such as working on collections of objects (<code>dart:collection</code>), making calculations (<code>dart:math</code>), and encoding/decoding data (<code>dart:convert</code>). Additional APIs are available in <a href="/resources/useful-packages">commonly used packages</a>.</p><div class="header-wrapper"><h2 id="library-tour">Library tour</h2><a class="heading-link" href="#library-tour" aria-label="Link to 'Library tour' section">#</a></div><p>The following guides cover how to use major features of Dart's core libraries. They provide just an overview, and are by no means comprehensive. Whenever you need more details about a library or its members, consult the <a href="https://api.dart.dev">Dart API reference.</a></p><dl><dt><a href="/libraries/dart-core">dart:core</a></dt><dd>Built-in types, collections, and other core functionality. This library is automatically imported into every Dart program.</dd><dt><a href="/libraries/dart-async">dart:async</a></dt><dd>Support for asynchronous programming, with classes such as Future and Stream.</dd><dt><a href="/libraries/dart-math">dart:math</a></dt><dd>Mathematical constants and functions, plus a random number generator.</dd><dt><a href="/libraries/dart-convert">dart:convert</a></dt><dd>Encoders and decoders for converting between different data representations, including JSON and UTF-8.</dd><dt><a href="/libraries/dart-io">dart:io</a></dt><dd>I/O for programs that can use the Dart VM, including Flutter apps, servers, and command-line scripts.</dd><dt><a href="/interop/js-interop">dart:js_interop</a></dt><dd>APIs for interop with the web platform. Along with <code>package:web</code>, <code>dart:js_interop</code> replaces <code>dart:html</code>.</dd></dl><p>As mentioned, these pages are just an overview; they cover only a few dart:* libraries and no third-party libraries.</p><p>For an overview of all libraries that Dart supports on different platforms, check out the <a href="#multi-platform-libraries">Multi-platform libraries</a>, <a href="#native-platform-libraries">Native platform libraries</a>, and <a href="#web-platform-libraries">Web platform libraries</a> lists below.</p><p>Other places to find library information are the <a href="https://pub.dev">pub.dev site</a> and the <a href="/web/libraries">Dart web developer library guide</a>. You can find API documentation for all dart:* libraries in the <a href="https://api.dart.dev">Dart API reference</a> or, if you're using Flutter, the <a href="https://api.flutter.dev">Flutter API reference</a>.</p><p>To learn more about the Dart language, check out the <a href="/language">language documentation and samples</a>.</p><div class="header-wrapper"><h2 id="multi-platform-libraries">Multi-platform libraries</h2><a class="heading-link" href="#multi-platform-libraries" aria-label="Link to 'Multi-platform libraries' section">#</a></div><p>The following table lists the Dart core libraries that work on all <a href="/overview#platform">Dart platforms</a>.</p><div class="table-wrapper"><table class="table table-striped"><thead><tr><th>Library</th><th>Notes</th></tr></thead><tbody><tr><td><a href="https://api.dart.dev/dart-core/dart-core-library.html"><code>dart:core</code></a><br>Built-in types, collections, and other core functionality for every Dart program.</td><td></td></tr><tr><td><a href="https://api.dart.dev/dart-async/dart-async-library.html"><code>dart:async</code></a>, <a href="https://pub.dev/packages/async"><code>package:async</code></a><br>Support for asynchronous programming, with classes such as <code>Future</code> and <code>Stream</code>.<br><code>package:async</code> provides additional utilities around the <code>Future</code> and <code>Stream</code> types.</td><td></td></tr><tr><td><a href="https://api.dart.dev/dart-collection/dart-collection-library.html"><code>dart:collection</code></a>, <a href="https://pub.dev/packages/collection"><code>package:collection</code></a><br>Classes and utilities that supplement the collection support in <code>dart:core</code>.<br><code>package:collection</code> provides further collection implementations and functions for working on and with collections.</td><td></td></tr><tr><td><a href="https://api.dart.dev/dart-convert/dart-convert-library.html"><code>dart:convert</code></a>, <a href="https://pub.dev/packages/convert"><code>package:convert</code></a><br>Encoders and decoders for converting between different data representations, including JSON and UTF-8.<br><code>package:convert</code> provides additional encoders and decoders.</td><td></td></tr><tr><td><a href="https://api.dart.dev/dart-developer/dart-developer-library.html"><code>dart:developer</code></a><br>Interaction with developer tools such as the debugger and inspector.</td><td><a href="/overview#native-platform">Native JIT</a> and the <a href="/tools/webdev#serve">development JavaScript compiler</a> only</td></tr><tr><td><a href="https://api.dart.dev/dart-math/dart-math-library.html"><code>dart:math</code></a><br>Mathematical constants and functions, plus a random number generator.</td><td></td></tr><tr><td><a href="https://api.dart.dev/dart-typed_data/dart-typed_data-library.html"><code>dart:typed_data</code></a>, <a href="https://pub.dev/packages/typed_data"><code>package:typed_data</code></a><br>Lists that efficiently handle fixed sized data (for example, unsigned 8-byte integers) and SIMD numeric types.<br><code>package:typed_data</code> provides further classes and functions working on typed data.</td><td></td></tr></tbody></table></div><div class="header-wrapper"><h2 id="native-platform-libraries">Native platform libraries</h2><a class="heading-link" href="#native-platform-libraries" aria-label="Link to 'Native platform libraries' section">#</a></div><p>The following table lists the Dart core libraries that work on the <a href="/overview#native-platform">Dart native platform</a> (AOT- and JIT-compiled code).</p><div class="table-wrapper"><table class="table table-striped"><thead><tr><th>Library</th><th>Notes</th></tr></thead><tbody><tr><td><a href="https://api.dart.dev/dart-ffi/dart-ffi-library.html"><code>dart:ffi</code></a>, <a href="https://pub.dev/packages/ffi"><code>package:ffi</code></a><br>A foreign function interface that lets Dart code use native C APIs.<br><code>package:ffi</code> contains utilities incl. support for converting Dart strings and C strings.</td><td></td></tr><tr><td><a href="https://api.dart.dev/dart-io/dart-io-library.html"><code>dart:io</code></a>, <a href="https://pub.dev/packages/io"><code>package:io</code></a><br>File, socket, HTTP, and other I/O support for non-web applications.<br><code>package:io</code> provides functionality including support for ANSI colors, file copying, and standard exit codes.</td><td></td></tr><tr><td><a href="https://api.dart.dev/dart-isolate/dart-isolate-library.html"><code>dart:isolate</code></a><br>Concurrent programming using isolates: independent workers similar to threads.</td><td></td></tr><tr><td><a href="https://api.dart.dev/dart-mirrors/dart-mirrors-library.html"><code>dart:mirrors</code></a><br>Basic reflection with support for introspection and dynamic invocation.</td><td>Experimental<br><a href="/overview#native-platform">Native JIT</a> only (<em>not</em>聽Flutter)</td></tr></tbody></table></div><div class="header-wrapper"><h2 id="web-platform-libraries">Web platform libraries</h2><a class="heading-link" href="#web-platform-libraries" aria-label="Link to 'Web platform libraries' section">#</a></div><p>The following table lists the Dart core libraries that work on the <a href="/overview#web-platform">Dart web platform</a> (code compiled to JavaScript). The latest, recommended tools are <strong>bolded</strong>, and legacy tools are <em>italicized</em> (visit <a href="/interop/js-interop">Javascript interoperability</a> for more information).</p><div class="table-wrapper"><table class="table table-striped"><thead><tr><th>Library</th><th>Notes</th></tr></thead><tbody><tr><td><a href="https://pub.dev/packages/web"><strong><code>package:web</code></strong></a><br>Lightweight browser API bindings built around JS interop</td><td>Replaces all <code>dart:*</code> web libraries. Read the <a href="/interop/js-interop/package-web">migration guide</a>.</td></tr><tr><td><a href="https://api.dart.dev/dart-js_interop/dart-js_interop-library.html"><strong><code>dart:js_interop</code></strong></a><br>Interop with JavaScript and browser APIs.</td><td>Replaces <code>package:js</code>.</td></tr><tr><td><a href="https://api.dart.dev/dart-js_interop_unsafe/dart-js_interop_unsafe-library.html"><strong><code>dart:js_interop_unsafe</code></strong></a><br>Utility methods to manipulate JavaScript objects dynamically.</td><td>Replaces <code>dart:js_util</code>.</td></tr><tr><td><a href="https://api.dart.dev/dart-html/dart-html-library.html"><em><code>dart:html</code></em></a> <em>(legacy)</em><br>HTML elements and other resources for web-based applications.</td><td>Use <code>package:web</code> instead.</td></tr><tr><td><a href="https://api.dart.dev/dart-indexed_db/dart-indexed_db-library.html"><em><code>dart:indexed_db</code></em></a> <em>(legacy)</em><br>Client-side key-value store with support for indexes.</td><td>Use <code>package:web</code> instead.</td></tr><tr><td><a href="https://api.dart.dev/dart-js/dart-js-library.html"><em><code>dart:js</code></em></a>, <a href="https://api.dart.dev/dart-js_util/dart-js_util-library.html"><em><code>dart:js_util</code></em></a>, <a href="https://pub.dev/packages/js"><em><code>package:js</code></em></a> <em>(legacy)</em><br>Low-level primitives and higher-level annotations for JS interop.</td><td>Use <code>dart:js_interop</code> or <code>dart:js_interop_unsafe</code> instead.</td></tr><tr><td><a href="https://api.dart.dev/dart-svg/dart-svg-library.html"><em><code>dart:svg</code></em></a> <em>(legacy)</em><br>Scalable Vector Graphics.</td><td>Use <code>package:web</code> instead.</td></tr><tr><td><a href="https://api.dart.dev/dart-web_audio/dart-web_audio-library.html"><em><code>dart:web_audio</code></em></a> <em>(legacy)</em><br>High-fidelity audio programming in the browser.</td><td>Use <code>package:web</code> instead.</td></tr><tr><td><a href="https://api.dart.dev/dart-web_gl/dart-web_gl-library.html"><em><code>dart:web_gl</code></em></a> <em>(legacy)</em><br>3D programming in the browser.</td><td>Use <code>package:web</code> instead.</td></tr></tbody></table></div><nav id="prev-next"><ul><li class="previous"></li><li class="next"><a href="/libraries/dart-core">dart:core  &rang;</a></li></ul></nav><p id="page-github-links"><span>Unless stated otherwise, the documentation on this site reflects Dart 3.7.1. Page last updated on 2025-01-31.</span> <a href="https://github.com/dart-lang/site-www/tree/main/src/content/libraries/index.md" target="_blank" rel="noopener">View source</a> <span>or </span><a href="https://github.com/dart-lang/site-www/issues/new?template=1_page_issue.yml&page-url=https://dart.dev/libraries/&page-source=https://github.com/dart-lang/site-www/tree/main/src/content/libraries/index.md" title="Report an issue with this page" target="_blank" rel="noopener">report an issue</a>.</p></div></article></main></div><footer id="page-footer"><div class="footer-section footer-main"><a href="/" class="brand" title="Dart"><img src="/assets/img/logo/logo-white-text.svg" alt="Dart" width="164"></a><div class="footer-social-links"><a href="https://medium.com/dartlang" target="_blank" rel="noopener" title="Dart's Medium publication"><svg><use href="/assets/img/social/medium.svg#medium"></use></svg> </a><a href="https://github.com/dart-lang" target="_blank" rel="noopener" title="Dart's GitHub organization"><svg><use href="/assets/img/social/github.svg#github"></use></svg> </a><a href="https://bsky.app/profile/dart.dev" target="_blank" rel="noopener" title="Dart's Bluesky profile"><svg><use href="/assets/img/social/bluesky.svg#bluesky"></use></svg> </a><a href="https://twitter.com/dart_lang" target="_blank" rel="noopener" title="Dart's X (Twitter) profile"><svg><use href="/assets/img/social/x.svg#x"></use></svg></a></div></div><div class="footer-section footer-tray"><div class="footer-licenses">Except as otherwise noted, this site is licensed under a <a href="https://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution 4.0 International License</a>, and code samples are licensed under the <a href="https://opensource.org/licenses/BSD-3-Clause">3-Clause BSD License</a>.</div><div class="footer-utility-links"><ul><li><a href="/terms" title="Terms of use">Terms</a></li><li><a href="https://policies.google.com/privacy" target="_blank" rel="noopener" title="Privacy policy">Privacy</a></li><li><a href="/security" title="Security philosophy and practices">Security</a></li></ul></div></div></footer></div></body></html>