Contents

Dart's core libraries

Dart has a rich set of core libraries that provide essentials for many everyday programming tasks such as working on collections of objects (dart:collection), making calculations (dart:math), and encoding/decoding data (dart:convert). Additional APIs are available in commonly used packages.

Library tour

#

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 Dart API reference.

dart:core
Built-in types, collections, and other core functionality. This library is automatically imported into every Dart program.
dart:async
Support for asynchronous programming, with classes such as Future and Stream.
dart:math
Mathematical constants and functions, plus a random number generator.
dart:convert
Encoders and decoders for converting between different data representations, including JSON and UTF-8.
dart:io
I/O for programs that can use the Dart VM, including Flutter apps, servers, and command-line scripts.
dart:html
DOM and other APIs for browser-based apps.

As mentioned, these pages are just an overview; they cover only a few dart:* libraries and no third-party libraries.

For an overview of all libraries that Dart supports on different platforms, check out the Multi-platform libraries, Native platform libraries, and Web platform libraries lists below.

Other places to find library information are the pub.dev site and the Dart web developer library guide. You can find API documentation for all dart:* libraries in the Dart API reference or, if you're using Flutter, the Flutter API reference.

To learn more about the Dart language, check out the language documentation and samples.

Multi-platform libraries

#

The following table lists the Dart core libraries that work on all Dart platforms.

LibraryNotes
dart:core
Built-in types, collections, and other core functionality for every Dart program.
dart:async, package:async
Support for asynchronous programming, with classes such as Future and Stream.
package:async provides additional utilities around the Future and Stream types.
dart:collection, package:collection
Classes and utilities that supplement the collection support in dart:core.
package:collection provides further collection implementations and functions for working on and with collections.
dart:convert, package:convert
Encoders and decoders for converting between different data representations, including JSON and UTF-8.
package:convert provides additional encoders and decoders.
dart:developer
Interaction with developer tools such as the debugger and inspector.
Native JIT and the development JavaScript compiler only
dart:math
Mathematical constants and functions, plus a random number generator.
dart:typed_data, package:typed_data
Lists that efficiently handle fixed sized data (for example, unsigned 8-byte integers) and SIMD numeric types.
package:typed_data provides further classes and functions working on typed data.

Native platform libraries

#

The following table lists the Dart core libraries that work on the Dart native platform (AOT- and JIT-compiled code).

LibraryNotes
dart:ffi, package:ffi
A foreign function interface that lets Dart code use native C APIs.
package:ffi contains utilities incl. support for converting Dart strings and C strings.
dart:io, package:io
File, socket, HTTP, and other I/O support for non-web applications.
package:io provides functionality including support for ANSI colors, file copying, and standard exit codes.
dart:isolate
Concurrent programming using isolates: independent workers similar to threads.
dart:mirrors
Basic reflection with support for introspection and dynamic invocation.
Experimental
Native JIT only (not Flutter)

Web platform libraries

#

The following table lists the Dart core libraries that work on the Dart web platform (code compiled to JavaScript).

LibraryNotes
dart:html
HTML elements and other resources for web-based applications.
dart:indexed_db
Client-side key-value store with support for indexes.
dart:js, dart:js_util, package:js
dart:js_util provides low-level primitives for interoperability; typically the higher-level annotations in package:js are recommended, as they help express interoperability more succinctly. For more details see JavaScript interoperability.
Don't use dart:js directly; direct use of those legacy APIs is deprecated.
dart:svg
Scalable Vector Graphics.
dart:web_audio
High-fidelity audio programming in the browser.
dart:web_gl
3D programming in the browser.