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.

Multi-platform libraries

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

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

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:io
File, socket, HTTP, and other I/O support for non-web applications.		 
dart:isolate
Concurrent programming using isolates: independent workers similar to threads.		 
dart:mirrors
Basic reflection with support for introspection and dynamic invocation.		Experimental
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:web_audio
High-fidelity audio programming in the browser.		 
dart:web_gl
3D programming in the browser.		 
dart:js
Don’t use. Instead, use the js package, as described in JavaScript interoperability.		DEPRECATED
dart:js_util
Don’t use. Instead, use the js package, as described in JavaScript interoperability.		DEPRECATED
dart:web_sql
API for storing data in the browser that can be queried with SQL.		DEPRECATED