Stopwatch

Stopwatch is a precise browser-based timer with lap tracking. Record lap times, view split times (time since previous lap), and see the fastest and slowest laps highlighted for easy analysis.

The timer uses performance.now() for sub-millisecond accuracy, avoiding the drift that affects setInterval-based timers. Results can be copied as a formatted list for pasting into a spreadsheet or document.

Works entirely in the browser tab. No install, no account. Useful for timing experiments, races, workouts, cooking, or any activity requiring precise elapsed time measurement.