Playwright

Playwright is the browser testing framework that made Selenium feel like a fax machine. From Microsoft, it supports Chromium, Firefox, and WebKit with a single API, auto-waits for elements, and runs tests in parallel out of the box. It's the new default for E2E testing.

Cypress is the popular alternative with a great UI but limited to Chromium-based browsers and can't handle multiple tabs. Puppeteer is Chrome-only and focused on automation, not testing. Selenium supports everything but the API is painful. For commercial, LambdaTest and BrowserStack offer cloud infrastructure.

If you're writing E2E tests for a web app, start with Playwright. The codegen tool records your clicks and generates tests. Trace viewer gives you a full timeline of what happened when a test fails. The test runner is fast and the API is clean.

The catch: the learning curve for advanced features (fixtures, page object models, custom matchers) is real. Test flakiness is better than Cypress but not zero — you'll still fight timing issues. And the tooling moves fast, so expect breaking changes between major versions.