web-platform-tests is a cross-browser test suite for validating Web platform specification implementations across WHATWG, W3C, and related standards.
The project addresses the need for browsers to verify compatibility with each other and with Web specifications. It provides a unified set of tests that can run across all major browsers, giving browser vendors confidence that their implementations align with standards and with each other. This shared test infrastructure eliminates the need for each browser project to maintain separate test suites and allows Web developers to rely on consistent platform behavior across implementations.
The tool suits anyone involved in browser development, standards implementation, or Web platform testing. Browser vendors use it to validate their implementations against the specification suite. Web developers and standards bodies benefit from the public test results archived at wpt.fyi, which tracks how different browsers perform on the same tests. The project provides multiple entry points: a public deployment at wpt.live allows running tests directly in any browser, while the command-line tools support local development workflows including test serving, linting, manifest generation, and browser automation.
Development activity shows sustained engagement across multiple channels. The project maintains active discussion forums including a real-time chat room with global participation and a low-traffic public mailing list for infrastructure topics. An RFC repository exists for proposing substantial changes that affect stakeholders. The codebase experiences frequent branch creation and deletion, reflecting active development and pull request activity. Documentation is comprehensive and centralized on the project's website, covering setup, test writing, peer review processes, and administrative procedures.
