This documentation covers Dart 1.24. For the Dart 2 API reference, see

Welcome to the Dart API reference documentation, covering the official Dart API libraries. Some of the most fundamental Dart libraries include:

  • dart:core: Core functionality such as strings, numbers, collections, errors, dates, and URIs.
  • dart:html: DOM manipulation for web apps.
  • dart:io: I/O for command-line apps.

Except for dart:core, you must import a library before you can use it. Here's an example of importing dart:html and dart:math:

import 'dart:html';
import 'dart:math';

You can install more libraries using the pub package manager. For information on finding, using, and publishing libraries with pub, see

The main site for learning and using Dart is Check out these additional pages:

This API reference is automatically generated from the source code in the Dart project. If you'd like to contribute to this documentation, see Contributing.



Support for asynchronous programming, with classes such as Future and Stream.


Classes and utilities that supplement the collection support in dart:core.


Encoders and decoders for converting between different data representations, including JSON and UTF-8.


Built-in types, collections, and other core functionality for every Dart program.


Interact with developer tools such as the debugger and inspector.


HTML elements and other resources for web-based applications that need to interact with the browser and the DOM (Document Object Model).


A client-side key-value store with support for indexes.


File, socket, HTTP, and other I/O support for server applications.


Concurrent programming using isolates: independent workers that are similar to threads but don't share memory, communicating only via messages.


Support for interoperating with JavaScript.


Utility methods to efficiently manipulate typed JSInterop objects in cases where the name to call is not known at runtime. You should only use these methods when the same effect cannot be achieved with @JS annotations. These methods would be extension methods on JSObject if Dart supported extension methods.


Mathematical constants and functions, plus a random number generator.


Basic reflection in Dart, with support for introspection and dynamic invocation.


Scalable Vector Graphics: Two-dimensional vector graphics with support for events and animation.


Lists that efficiently handle fixed sized data (for example, unsigned 8 byte integers) and SIMD numeric types.


High-fidelity audio programming in the browser.


3D programming in the browser.


An API for storing data in the browser that can be queried with SQL.