Free Online Stopwatch
Precise to the hundredth of a second, with lap splits — no app install, no account.
Laps
How to use the stopwatch
- Hit Start to begin timing; the button becomes Pause.
- Tap Lap any time to record a split without stopping the clock.
- Hit Reset to zero everything and clear the lap list.
Timing tips
This stopwatch measures with the browser's high-resolution clock, so it stays accurate even if the tab is briefly in the background — though keeping the tab visible gives the smoothest display. Laps record two numbers: the split (time since the last lap) and the running total, which is exactly what coaches and runners need for interval analysis. For experiments or cooking, note the hundredths digit only when it matters; human reaction time on the button is around two-tenths of a second, so do not over-interpret the last digit in hand-timed sprints. If you need repeated timed intervals with breaks instead — workouts, study sessions, presentations — the Pomodoro timer on this site handles work/break cycles. And because everything runs locally, the stopwatch keeps working if your connection drops mid-timing.
Frequently asked questions
How accurate is this stopwatch?
It uses performance.now(), accurate to a fraction of a millisecond. Display updates roughly every 30ms; the underlying measurement stays precise.
Does it keep running if I switch tabs?
Yes — timing is based on timestamps, not on the display updating, so backgrounding the tab does not lose time.
What is the difference between lap and split times?
Each lap shows the split (elapsed since the previous lap) and the total elapsed time, so you get both per-interval and cumulative views.
Is there a limit to the number of laps?
No practical limit — record as many as you need. Reset clears the list.