# Introducing package:flutter_lints > Migrate to package:flutter_lints to get the latest set of recommended lints, which encourage good coding practices. :::important These breaking change docs are accurate, as of the release under which they are published. Over time, the workarounds described here might become inaccurate. We don't, in general, keep these breaking change docs up to date as of each release. The [breaking change index file](/release/breaking-changes) lists the docs created for each release. ::: ## Summary The [`package:flutter_lints`][] defines the latest set of recommended lints that encourage good coding practices for Flutter apps, packages, and plugins. Projects created with `flutter create` using Flutter version 2.5 or newer are already enabled to use the latest set of recommended lints. Projects created prior to that version can upgrade to it with the instructions in this guide. ## Context Prior to the introduction of `package:flutter_lints`, the Flutter framework shipped with a set of lints defined in [`analysis_options_user.yaml`][] that was used by the [dart analyzer][] to identify code issues if a Flutter project didn't define a custom `analysis_options.yaml` file. Since `analysis_options_user.yaml` was tied to a particular framework version, it was difficult to evolve without breaking existing apps, packages, and plugins. As a result of that, the lints defined in `analysis_options_user.yaml` are heavily outdated. To fix this, `package:flutter_lints` was created. The package versions the lint set to enable evolving it without breaking existing projects. Since the package builds on Dart's [`package:lints`][] it also aligns the lints recommended for Flutter projects with the rest of the Dart ecosystem. ## Migration guide Follow these steps to migrate your Flutter project to use the latest recommended lints from `package:flutter_lints`: Add a dev_dependency on `package:flutter_lints` to your project's `pubspec.yaml` by running `flutter pub add --dev flutter_lints` in the root directory of the project. Create an `analysis_options.yaml` file in the root directory of your project (next to the `pubspec.yaml` file) with the following content: ```yaml include: package:flutter_lints/flutter.yaml ``` The newly activated lint set may identify some new issues in your code. To find them, open your project in an [IDE with Dart support][] or run `flutter analyze` on the command line. You may be able to fix some of the reported issues automatically by running `dart fix --apply` in the root directory of your project. ### Existing custom analysis_options.yaml file If your project already has a custom `analysis_options.yaml` file at its root, add `include: package:flutter_lints/flutter.yaml` to it at the top to activate the lints from `package:flutter_lints`. If your `analysis_options.yaml` already contains an `include:` directive you have to decide whether you want to keep those lints or whether you want to replace it with the lints from `package:flutter_lints` because the Dart analyzer only supports one `include:` directive per `analysis_options.yaml` file. ## Customizing the lints The lints activated for a given project can be further customized in the `analysis_options.yaml` file. This is shown in the example file below, which is a reproduction of the `analysis_options.yaml` file generated by `flutter create` for new projects. ```yaml # This file configures the analyzer, which statically analyzes Dart code to # check for errors, warnings, and lints. # # The issues identified by the analyzer are surfaced in the UI of Dart-enabled # IDEs (https://dart.dev/tools#ides-and-editors). The analyzer can also be # invoked from the command line by running `flutter analyze`. # The following line activates a set of recommended lints for Flutter apps, # packages, and plugins designed to encourage good coding practices. include: package:flutter_lints/flutter.yaml linter: # The lint rules applied to this project can be customized in the # section below to disable rules from the `package:flutter_lints/flutter.yaml` # included above or to enable additional rules. A list of all available lints # and their documentation is published at # https://dart-lang.github.io/linter/lints/index.html. # # Instead of disabling a lint rule for the entire project in the # section below, it can also be suppressed for a single line of code # or a specific dart file by using the `// ignore: name_of_lint` and # `// ignore_for_file: name_of_lint` syntax on the line or in the file # producing the lint. rules: # avoid_print: false # Uncomment to disable the `avoid_print` rule # prefer_single_quotes: true # Uncomment to enable the `prefer_single_quotes` rule # Additional information about this file can be found at # https://dart.dev/guides/language/analysis-options ``` ## Timeline Landed in version: 2.3.0-12.0.pre
In stable release: 2.5 ## References Documentation: * [`package:flutter_lints`][] * [Package dependencies][] * [Customizing static analysis][] Relevant issue: * [Issue 78432 - Update lint set for Flutter applications][] Relevant PRs: * [Add flutter_lints package][] * [Integrate package:flutter_lints into templates][] [Add flutter_lints package]: https://github.com/flutter/packages/pull/343 [`analysis_options_user.yaml`]: https://github.com/flutter/flutter/blob/main/packages/flutter/lib/analysis_options_user.yaml [Customizing static analysis]: https://dart.dev/guides/language/analysis-options [dart analyzer]: https://dart.dev/guides/language/analysis-options [IDE with Dart support]: https://dart.dev/tools#ides-and-editors [Integrate package:flutter_lints into templates]: https://github.com/flutter/flutter/pull/81417 [Issue 78432 - Update lint set for Flutter applications]: https://github.com/flutter/flutter/issues/78432 [`package:flutter_lints`]: https://pub.dev/packages/flutter_lints [`package:lints`]: https://pub.dev/packages/lints [Package dependencies]: https://dart.dev/tools/pub/dependencies