Shortcuts: Space=Start/Stop · L=Lap · R=Reset
This online stopwatch uses JavaScript's requestAnimationFrame API, displaying millisecond precision with ~10ms update intervals. Typical accuracy ranges from 10-50ms depending on your browser and system performance, which is sufficient for everyday timing, sports training, and cooking. Microsecond precision requires dedicated hardware timers.
This stopwatch supports: Spacebar — Start/Pause the stopwatch; L key — Record a lap; R key — Reset the stopwatch. These shortcuts let you control the timer without clicking buttons, which is especially useful during workouts or experiments.
A stopwatch counts upward from zero to measure elapsed time, ideal for timing runs, experiments, or cooking. A countdown timer counts down from a set time to zero, used for reminders or time-limited activities. This is a stopwatch — we also have a separate countdown timer tool.
The Lap feature records split times while the stopwatch runs. Click 'Lap' (or press L) to capture the current time and calculate the interval since your last lap. This is useful for tracking running splits, experiment intervals, or any activity where you need segment timing.
No. This stopwatch runs entirely in your browser — no timing data is uploaded to any server. All timing logic executes client-side in JavaScript. Data is lost when you close the page. This privacy-first design ensures your timing data stays only on your device.