Chronometer

A precise stopwatch with lap times. Uses requestAnimationFrame and performance.now() for accurate timing in the browser.

00:00:00.000

Frequently Asked Questions

The stopwatch uses requestAnimationFrame for display updates and performance.now() for time measurement, which provides sub-millisecond accuracy. Actual precision depends on your browser and system, but is typically within 1–5ms.
A lap time is the duration of a single interval (from the previous lap or start). A split time is the total elapsed time from the start. Both are shown in the laps table for each recorded lap.
Yes. The elapsed time is calculated from absolute timestamps (performance.now), so even if the browser throttles animation frames in background tabs, the displayed time will be correct when you return.