Welcome to the Flutter API reference documentation.
Flutter is Google’s mobile UI framework for crafting high-quality native interfaces on iOS and Android in record time. Flutter works with existing code, is used by developers and organizations around the world, and is free and open source.
The API reference herein covers all libraries that are exported by the Flutter SDK.
More Documentation
This site hosts Flutter's API documentation. Other documentation can be found at the following locations:
- flutter.io (main site)
- Installation
- Codelabs
- Contributing to Flutter
Importing a Library
Framework Libraries
Libraries in the "Libraries" section below (or in the left navigation) are part
of the core Flutter framework and are imported using
'package:flutter/<library>.dart', like so:
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
Dart Libraries
Libraries in the "Dart" section exist in the 'dart:' namespace and are imported
using 'dart:<library>', like so:
import 'dart:async';
import 'dart:ui';
Except for 'dart:core', you must import a Dart library before you can use it.
Other Libraries
Libraries in other sections are supporting libraries that ship with Flutter.
They are organized by package and are imported using
'package:<package>/<library>.dart', like so:
import 'package:flutter_test/flutter_test.dart';
import 'package:file/local.dart';
Finding Other Libraries
Flutter has a rich community of packages that have been contributed by the open-source community. You can browse those packages at pub.dartlang.org