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href="/guides/language/spec">Language specification</a></li><li class="nav-item"><a class="nav-link" href="/resources/dart-3-migration">Dart 3 migration guide</a></li><li class="nav-item"><a class="nav-link collapsible collapsed" data-toggle="collapse" data-target="#sidenav-9-6" href="#sidenav-9-6" role="button" aria-expanded="false" aria-controls="sidenav-9-6">Coming from ...</a><ul class="nav flex-column flex-nowrap collapse" id="sidenav-9-6"><li class="nav-item"><a class="nav-link" href="/resources/coming-from/js-to-dart">JavaScript to Dart</a></li><li class="nav-item"><a class="nav-link" href="/resources/coming-from/swift-to-dart">Swift to Dart</a></li></ul></li><div class="dropdown-divider"></div><li class="nav-item"><a class="nav-link" href="/resources/faq">FAQ</a></li><li class="nav-item"><a class="nav-link" href="/resources/glossary">Glossary</a></li><li class="nav-item"><a class="nav-link" href="/resources/books">Books</a></li><li class="nav-item"><a class="nav-link" href="/resources/videos">Videos</a></li><li class="nav-item"><a class="nav-link" href="/tutorials">Tutorials</a></li></ul></li><li class="nav-item"><a class="nav-link collapsible" data-toggle="collapse" href="#sidenav-10" role="button" aria-expanded="true" aria-controls="sidenav-10">Related sites</a><ul class="nav flex-column flex-nowrap collapse show" id="sidenav-10"><li class="nav-item"><a class="nav-link" href="https://api.dart.dev" target="_blank" rel="noopener">API reference</a></li><li class="nav-item"><a class="nav-link" href="https://medium.com/dartlang" target="_blank" rel="noopener">Blog</a></li><li class="nav-item"><a class="nav-link" href="https://dartpad.dev" target="_blank" rel="noopener">DartPad (online editor)</a></li><li class="nav-item"><a class="nav-link" href="https://flutter.dev" target="_blank" rel="noopener">Flutter</a></li><li class="nav-item"><a class="nav-link" href="https://pub.dev" target="_blank" rel="noopener">Package site</a></li></ul></li></ul></div></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"><nav id="subnav"><ul><li class="previous"></li><li class="next"><a href="/libraries/dart-core">dart:core  &rang;</a></li></ul></nav><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="/libraries/dart-html">dart:html</a></dt><dd>DOM and other APIs for browser-based apps. We now recommend using <code>package:web</code> over <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="subnav"><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 3.5.4. 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