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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 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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 active collapsible" data-toggle="collapse" data-target="#-sidenav-7" role="button" aria-expanded="true" aria-controls="-sidenav-7"><span>Tools & techniques</span> <span class="material-symbols expander" aria-hidden="true">expand_more</span></button><ul class="nav collapse show" 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 active collapsible" data-toggle="collapse" data-target="#-sidenav-7-2" role="button" aria-expanded="true" 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 show" 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 active collapsible" data-toggle="collapse" data-target="#-sidenav-7-2-4" role="button" aria-expanded="true" 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 show" 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 active" 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="/deprecated/sound-problems"><div><span>Fixing common type problems</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="#embedded-dartpads-dont-appear">Embedded DartPads don't appear</a></li><li class="toc-entry nav-item"><a class="nav-link" href="#code-doesnt-work-outside-dartpad">Code doesn't work outside DartPad</a></li><li class="toc-entry nav-item"><a class="nav-link" href="#previously-working-code-now-has-errors">Previously working code now has errors</a></li><li class="toc-entry nav-item"><a class="nav-link" href="#dartpad-doesnt-work-in-china">DartPad doesn't work in China</a></li><li class="toc-entry nav-item"><a class="nav-link" href="#other-issues">Other issues</a></li></ul></div><article><div class="content"><div id="site-content-title"><h1>Troubleshooting DartPad</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="#embedded-dartpads-dont-appear">Embedded DartPads don't appear</a></li><li class="toc-entry"><a href="#code-doesnt-work-outside-dartpad">Code doesn't work outside DartPad</a></li><li class="toc-entry"><a href="#previously-working-code-now-has-errors">Previously working code now has errors</a></li><li class="toc-entry"><a href="#dartpad-doesnt-work-in-china">DartPad doesn't work in China</a></li><li class="toc-entry"><a href="#other-issues">Other issues</a></li></ul></div><p>This page describes solutions to problems that might occur when you're trying to use DartPad, whether at <a href="https://dartpad.dev">dartpad.dev</a> or in a page that has embedded DartPads. For an overview of DartPad, see the <a href="/tools/dartpad">DartPad page</a>.</p><div class="header-wrapper"><h2 id="embedded-dartpads-dont-appear">Embedded DartPads don't appear</h2><a class="heading-link" href="#embedded-dartpads-dont-appear" aria-label="Link to 'Embedded DartPads don't appear' section">#</a></div><p>The dart.dev homepage and many tutorials have embedded DartPads. If these DartPads don't appear at all, then try the following:</p><ul><li><p>Make sure you're using one of the latest two versions of Chrome, Edge, Firefox, or Safari. DartPad might not work in other browsers, and is known not to work in the default configuration of the Brave browser.</p></li><li><p>If you're using an ad blocker, disable it.</p></li><li><p>Check whether you've disabled third-party tracking cookies (<a href="https://support.google.com/chrome/answer/95647">Chrome instructions</a>). If you've disabled cookies, change your settings to <strong>allow cookies for dartpad.dev</strong>. If you're using embedded DartPads, such as in the <a href="/resources/dart-cheatsheet">Dart cheatsheet</a> or the <a href="https://docs.flutter.dev/codelabs/implicit-animations">implicit animations codelab</a>, you might need to allow cookies for the embedding site domain, as well (in these cases, <strong>dart.dev</strong> and <strong>docs.flutter.dev</strong>, respectively).</p></li><li><p>If you repeatedly reload a page that contains embedded DartPads, then you might run into <a href="https://docs.github.com/en/rest/overview/resources-in-the-rest-api#rate-limiting">GitHub rate limiting.</a> Within 60 minutes, you should be able to reload the page and see code in the embedded DartPads.</p></li></ul><p>Although DartPad doesn't use cookies, it does rely on local storage, which browsers usually disable when cookies are disabled.</p><div class="header-wrapper"><h2 id="code-doesnt-work-outside-dartpad">Code doesn't work outside DartPad</h2><a class="heading-link" href="#code-doesnt-work-outside-dartpad" aria-label="Link to 'Code doesn't work outside DartPad' section">#</a></div><p>If you copy code from DartPad into another environment, the code might not run successfully. Here are some possible causes and fixes:</p><ul><li><p>If Dart can't find an imported library, make sure you've added all necessary package dependencies. DartPad includes many built-in packages by default, but your own project must explicitly list the packages that it depends on. To see the packages that DartPad includes, go to <a href="https://dartpad.dev">dartpad.dev</a> and click the <strong>i</strong> icon at the bottom right of the window. To learn more about adding package dependencies to your own project, see the documentation for <a href="/tools/pub/cmd/pub-add"><code>dart pub add</code></a>.</p></li><li><p>If Dart can't find certain methods or properties, check the code included provided alongside the exercise.</p></li><li><p>If the code has other compilation errors, make sure you're using the latest stable version of the Dart SDK. DartPad and embedded samples generally use the latest stable release of the SDK, and older versions might be missing necessary language or library features. To learn how to update the Dart SDK, see <a href="/get-dart">Get the Dart SDK</a>.</p></li><li><p>If you're creating a web app, make sure you have the proper project setup. DartPad doesn't show all the necessary markup to run Dart code. To get started creating web apps with Dart, check out <a href="/web/get-started">Build a web app with Dart</a>.</p></li></ul><div class="header-wrapper"><h2 id="previously-working-code-now-has-errors">Previously working code now has errors</h2><a class="heading-link" href="#previously-working-code-now-has-errors" aria-label="Link to 'Previously working code now has errors' section">#</a></div><p>If the code is using language or library features no longer supported in the latest stable release of Dart, the code may no longer analyze or run without errors.</p><ul><li>If possible, update the code to work with the latest Dart release, as DartPad only supports the <strong>stable</strong> and <strong>beta</strong> channels.</li><li>If the code worked in an earlier Dart release, you can use that version of Dart locally. To learn how to install a specific version of Dart, check out <a href="/get-dart">Get the Dart SDK</a>.</li></ul><div class="header-wrapper"><h2 id="dartpad-doesnt-work-in-china">DartPad doesn't work in China</h2><a class="heading-link" href="#dartpad-doesnt-work-in-china" aria-label="Link to 'DartPad doesn't work in China' section">#</a></div><p>Try <a href="https://dartpad.cn">dartpad.cn.</a></p><div class="header-wrapper"><h2 id="other-issues">Other issues</h2><a class="heading-link" href="#other-issues" aria-label="Link to 'Other issues' section">#</a></div><p>If you have any other problems when using DartPad, <a href="https://github.com/dart-lang/dart-pad/issues/new">create an issue on GitHub.</a></p><p id="page-github-links"><span>Unless stated otherwise, the documentation on this site reflects Dart 3.7.0. Page last updated on 2024-06-10.</span> <a href="https://github.com/dart-lang/site-www/tree/main/src/content/tools/dartpad/troubleshoot.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/tools/dartpad/troubleshoot/&page-source=https://github.com/dart-lang/site-www/tree/main/src/content/tools/dartpad/troubleshoot.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>