Web Test Runner is a free test runner for web applications, installed as an npm development dependency. It runs tests in parallel, keeping each test file in its own browser environment. Headless browser launchers include Puppeteer, Playwright, Selenium, BrowserStack, and WebdriverIO; Playwright supports Chromium, Firefox, and WebKit, while BrowserStack offers remote runs. For debugging, it can open a browser window with developer tools and report browser logs, 404 responses, and errors. Its command line includes interactive watch mode, which reruns tests after file changes, and code coverage with configurable thresholds and reports. Coverage instrumentation defaults to Chromium. The runner can mock ES modules through import maps and includes a Mocha integration, plus instructions for creating a custom test framework. It is powered by esbuild and Rollup plugins. Modern Web publishes the project as open source under the MIT license, with packages in the @web npm namespace. The project documentation points to GitHub for help and feedback and welcomes documentation contributions.
Who it is for
It suits developers who need browser-based testing for web applications, including parallel test runs, coverage reports, or remote browser checks. Teams using Mocha or building a custom test framework can use its documented integrations.
What is good
- Runs test files in parallel and isolation
- Supports Chromium, Firefox, and WebKit through Playwright
- Watch mode reruns tests when files change
- Coverage includes configurable thresholds and reports
- Free and MIT-licensed
What to know first
- Default coverage instrumentation uses Chromium
- BrowserStack remote testing requires its launcher
- Installation is as an npm development dependency
Verdict
Web Test Runner combines isolated browser runs with debugging, watch mode, and coverage features. Its documented launchers span local and remote browser testing, while coverage defaults to Chromium.
Web Test Runner plans and pricing
All plansCompared on JavaScript testing frameworks
- Free plan
- Yes
- Component testing
- Yes
- Coverage reporting
- Yes
- Snapshot testing
- Yes
- Supported runtimes
- Chromium, Firefox, WebKit
- Parallel execution
- Yes
