Flutter is Google's SDK for crafting beautiful, fast user experiences for mobile, web, and desktop from a single codebase. Flutter works with existing code, is used by developers and organizations around the world, and is free and open source.
This API reference covers all libraries that are exported by the Flutter SDK.
This site hosts Flutter's API documentation. Other documentation can be found at the following locations:
In addition to the online sites above, Flutter's documentation can be downloaded as an HTML documentation ZIP file for use when offline or when you have a poor internet connection.
Warning: the offline documentation files are quite large, approximately 700 MB to 900 MB.
Offline HTML documentation ZIP bundles:
Or, you can add Flutter to the open-source Zeal app using the following XML configurations. Follow the instructions in the application for adding a feed.
Libraries in the "Libraries" section below (or in the left
navigation) are part of the core Flutter framework and are imported
'package:flutter/<library>.dart', like so:
import 'package:flutter/material.dart'; import 'package:flutter/services.dart';
Libraries in the "Dart" section exist in the
namespace and are imported using
import 'dart:async'; import 'dart:ui';
'dart:core', you must import a Dart library
before you can use it.
Libraries in other sections are supporting libraries that ship with
Flutter. They are organized by package and are imported using
import 'package:flutter_test/flutter_test.dart'; import 'package:file/local.dart';
Flutter has a rich ecosystem of packages that have been contributed by the Flutter team and the broader open source community to a central repository. Among the thousands of packages, you'll find support for Firebase, Google Fonts, hardware services like Bluetooth and camera, new widgets and animations, and integration with other popular web services. You can browse those packages at pub.dev.