Playwright
playwright.dev
Microsoft's end-to-end testing framework that controls Chromium, Firefox, and WebKit with a single API — with auto-waiting, network interception, parallel test execution, and a visual trace debugger.
Why it is useful
Auto-waiting eliminates the flaky sleep() calls that plague older Selenium tests — Playwright waits for elements to be actionable before interacting. The trace viewer lets you replay test failures step by step with DOM snapshots and network logs. Multiple browser contexts run in parallel without interference, enabling fast test suites. Widely considered the best browser automation tool available today.