Chapters1 Upgrading to Rails 8.0
If you're upgrading an existing application, it's a great idea to have good test coverage before going in. You should also first upgrade to Rails 7.2 in case you haven't and make sure your application still runs as expected before attempting an update to Rails 8.0. A list of things to watch out for when upgrading is available in the Upgrading Ruby on Rails guide.
2 Major Features
3 Railties
Please refer to the Changelog for detailed changes.
3.1 Removals
3.2 Deprecations
3.3 Notable changes
4 Action Cable
Please refer to the Changelog for detailed changes.
4.1 Removals
4.2 Deprecations
4.3 Notable changes
5 Action Pack
Please refer to the Changelog for detailed changes.
5.1 Removals
5.2 Deprecations
5.3 Notable changes
6 Action View
Please refer to the Changelog for detailed changes.
6.1 Removals
6.2 Deprecations
6.3 Notable changes
7 Action Mailer
Please refer to the Changelog for detailed changes.
7.1 Removals
7.2 Deprecations
7.3 Notable changes
8 Active Record
Please refer to the Changelog for detailed changes.
8.1 Removals
8.2 Deprecations
8.3 Notable changes
9 Active Storage
Please refer to the Changelog for detailed changes.
9.1 Removals
9.2 Deprecations
9.3 Notable changes
10 Active Model
Please refer to the Changelog for detailed changes.
10.1 Removals
10.2 Deprecations
10.3 Notable changes
11 Active Support
Please refer to the Changelog for detailed changes.
11.1 Removals
11.2 Deprecations
11.3 Notable changes
12 Active Job
Please refer to the Changelog for detailed changes.
12.1 Removals
12.2 Deprecations
12.3 Notable changes
13 Action Text
Please refer to the Changelog for detailed changes.
13.1 Removals
13.2 Deprecations
13.3 Notable changes
14 Action Mailbox
Please refer to the Changelog for detailed changes.
14.1 Removals
14.2 Deprecations
14.3 Notable changes
15 Ruby on Rails Guides
Please refer to the Changelog for detailed changes.
15.1 Notable changes
16 Credits
See the full list of contributors to Rails for the many people who spent many hours making Rails, the stable and robust framework it is. Kudos to all of them.
Feedback
You're encouraged to help improve the quality of this guide.
Please contribute if you see any typos or factual errors. To get started, you can read our documentation contributions section.
You may also find incomplete content or stuff that is not up to date. Please do add any missing documentation for main. Make sure to check Edge Guides first to verify if the issues are already fixed or not on the main branch. Check the Ruby on Rails Guides Guidelines for style and conventions.
If for whatever reason you spot something to fix but cannot patch it yourself, please open an issue.
And last but not least, any kind of discussion regarding Ruby on Rails documentation is very welcome on the official Ruby on Rails Forum.