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 community contributed packages.

The following table lists all of the Dart core libraries. Each library works on at least one platform.

Library Supported platforms
dart:async
Support for asynchronous programming, with classes such as Future and Stream.
All
dart:collection
Classes and utilities that supplement the collection support in dart:core.
All
dart:convert
Encoders and decoders for converting between different data representations, including JSON and UTF-8.
All
dart:core
Built-in types, collections, and other core functionality for every Dart program.
All
dart:developer
Interaction with developer tools such as the debugger and inspector.
JIT
Web (experimental, dartdevc only)
dart:html
HTML elements and other resources for web-based applications.
Web
dart:indexed_db
Client-side key-value store with support for indexes.
Web
dart:io
File, socket, HTTP, and other I/O support for non-web applications.
JIT
AOT
dart:isolate
Concurrent programming using isolates: independent workers similar to threads.
JIT
AOT
dart:js
Don’t use. Instead, use the js package, as described in JavaScript interoperability.
Web
dart:js_util
Don’t use. Instead, use the js package, as described in JavaScript interoperability.
Web
dart:math
Mathematical constants and functions, plus a random number generator.
All
dart:mirrors
Basic reflection with support for introspection and dynamic invocation.
JIT (experimental, not Flutter)
dart:typed_data
Lists that efficiently handle fixed sized data (for example, unsigned 8-byte integers) and SIMD numeric types.
All
dart:web_audio
High-fidelity audio programming in the browser.
Web
dart:web_gl
3D programming in the browser.
Web
dart:web_sql
API for storing data in the browser that can be queried with SQL.
Web (obsolete)