[Playwright] I conducted two tests on three browsers, and the completion time for each test varied. What is the reason for this?

Different browsers have different rendering engines, execution overhead, and resource usage. But I’d first check whether the tests run in parallel, whether the app or network introduces variability, and whether waits are deterministic. A test passing is not the same as a test performing consistently. Compare repeated runs, trace timings, and identify where the time is actually spent before optimizing.