web-platform-tests documentation

The web-platform-tests project is a W3C-coordinated attempt to build a cross-browser test suite for the Web-platform stack. Writing tests in a way that allows them to be run in all browsers gives browser projects confidence that they are shipping software which is compatible with other implementations, and that later implementations will be compatible with their implementations. This in turn gives Web authors/developers confidence that they can actually rely on the Web platform to deliver on the promise of working across browsers and devices without needing extra layers of abstraction to paper over the gaps left by specification editors and implementors.


If you get stuck or want clarification about anything, feel free to ask on either the mailing list or IRC (webclient, join channel #testing); IRC is generally busiest during the European working day but frequently has people on it at all times and should probably be the general first port of call for any help.

Watch a Talk

If you prefer watching a video, here is a talk introducing web-platform-tests:


GitHub is used both for issue tracking and test submissions; we provide a limited introduction to both git and GitHub.

Pull Requests are automatically labeled based on the directory the files they change are in; there are also comments added automatically to notify a number of people: this list of people comes from META.yml files in those same directories and their parents (i.e., they work recursively: a/META.yml will get notified for a/foo.html and a/b/bar.html).

If you want to be notified about changes to tests in a directory, feel free to add yourself to the META.yml file!