Cypress

Cypress runs end-to-end tests in a real browser with a UI that shows each step as it happens. No Selenium, no driver headaches: you write JavaScript, it clicks things, you watch it live. The test runner is MIT licensed and gives you time-travel debugging (step backward through a test), automatic waiting, network stubbing, component testing, and screenshots and video on failure.

Cypress Cloud is where the money is. It records CI runs and adds parallelization, Test Replay, flake detection and analytics. The free Starter plan includes all of that for up to 10 users and 500 recorded test results a month. A test result is one test case recorded from CI; local runs don't count.

Team is $75 a month, or $799 a year (about $67 a month), with 50 users and 120,000 test results a year; Business is $300 a month or $3,199 a year; extra results cost $6 per 1,000. Solo devs: the free runner and Starter are plenty. A team running 50 tests on 100 CI builds a month records 5,000 results and is well past Starter, so budget for Team. Playwright (microsoft/playwright) runs tests in parallel for free with no cloud required.

The catch: Cypress only tests what runs in a browser, so no native mobile, and it can't drive multiple browser tabs. And 500 results a month disappears fast once real CI starts recording.