Web Platform Tests
Web Platform Tests is an open-source cross-browser test suite for checking compatibility across web platform implementations.
What Web Platform Tests is
Web Platform Tests is an open-source cross-browser test suite for checking compatibility across web platform implementations. Anyone can run tests through the public wpt.live deployment in an internet-enabled browser, or clone the suite for local use on Linux, macOS, or Windows. The suite covers JavaScript APIs, rendering, crashes, WebDriver, and manual testing. Its command-line `wpt` tool runs tests in a selected browser and can produce machine-readable JSON reports and screenshots. It also supports saving and loading expected results for continuous integration and regression tracking. Regularly collected results from a range of browsers are archived at wpt.fyi. Local setup requires Python 3.9 or higher and configuration of test domains in the system hosts file. Running tests in multiple browser processes can make results less deterministic and add noise compared with the default single-process mode. The project is free, with a Free plan listed as free.
Good
- Public browser-based runner at wpt.live
- Covers APIs, rendering, crashes, WebDriver, and manual tests
- Command-line tool can produce JSON reports and screenshots
- Supports expected results for CI and regression tracking
- Results are archived at wpt.fyi
Watch out
- Local setup requires Python 3.9 or higher
- Local setup requires test-domain hosts-file configuration
- Multiple browser processes can make results less deterministic
Who it suits
Web Platform Tests suits browser projects and contributors who need to check web-platform behavior across implementations. It also fits teams running local or continuous-integration tests, provided they can meet the local setup requirements.
Verdict
Web Platform Tests offers both a public runner and a local test workflow, with results archived for browser comparison. Local environment requirements and extra noise from multiple browser processes are worth considering.
Plans and prices
From Web Platform Tests's own pricing page, checked 7 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Free | Free | Cross-browser test suite and public web runner |
The facts
Each one read from Web Platform Tests's own pages, with the date it was checked.
What it does
- CI integration
- The command-line interface supports saving and loading expected test results for continuous integration and regression tracking.checked 7 Oct 2026
- CI runs
- Contributors with repository write access can trigger full runs in the project’s CI systems, with results submitted to wpt.fyi.checked 7 Oct 2026
- Command line
- The wpt command can run tests in a chosen browser and supports machine-readable JSON reports and screenshots.checked 7 Oct 2026
- Execution limitation
- Running tests in multiple browser processes can make results less deterministic and introduce more noise than the default single-process mode.checked 7 Oct 2026
- Integrations
- GitHub is used for issue tracking and test submissions, and pull requests receive automatic labels and reviewer notifications based on directory metadata.checked 7 Oct 2026
- Local execution
- Tests can be cloned and run locally, and the project documents Windows, macOS, and Linux setup.checked 7 Oct 2026
- Public runner
- Anyone can run the tests by visiting the public deployment, wpt.live, in an internet-enabled browser.checked 7 Oct 2026
- Purpose
- Web Platform Tests is a cross-browser test suite for the Web platform, intended to help browser projects check compatibility across implementations.checked 7 Oct 2026
- Requirements
- Local setup requires Python 3.9 or higher and configuration of test domains in the system hosts file.checked 7 Oct 2026
- Review policy
- Test contributions are reviewed publicly, and each pull request needs approval from at least one project collaborator before merging.checked 7 Oct 2026
- Security
- The project documentation says SSL certificates for HTTPS-enabled domains are obtained through Let’s Encrypt.checked 7 Oct 2026
- Support
- The project directs users to its Matrix chat room and public low-traffic mailing list for questions.checked 7 Oct 2026
- Test archive
- wpt.fyi archives test results collected regularly from an array of web browsers.checked 7 Oct 2026
- Test types
- The suite includes JavaScript API tests, rendering tests, crash tests, WebDriver tests, and manual tests.checked 7 Oct 2026
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