Stopwatch
A simple online stopwatch with lap splits, accurate to a hundredth of a second. Start, stop and record laps; runs entirely in your browser, even offline.
00:00.00
Laps
No laps recorded yet.
How it works
The stopwatch measures elapsed time with your browser's high-resolution clock, so it stays accurate even when the tab is in the background. Press Lap to record a split without stopping; each lap shows both its own time and the cumulative total.
Nothing is sent anywhere and no times are saved between visits, the stopwatch runs entirely in your browser.
What this does
An online stopwatch measures elapsed time to a hundredth of a second, with lap splits you can record on the fly.
How to use it
- Press Start to begin timing.
- Press Lap to record a split.
- Press Stop to pause.
- Reset to clear and start again.
How it works
It measures elapsed time from your browser’s high-resolution clock rather than counting ticks, so the total stays accurate even when the tab is inactive.
Understanding your result
Elapsed time is read from a high-resolution clock rather than counted tick by tick, so the total stays accurate even if the tab is backgrounded or the screen sleeps. Each lap shows both its own split and the running total at that point, so the laps always add up to the overall time. Treat it as good to a few milliseconds, reliable for workouts and cooking, not for lab-grade timing.
Example
Press Lap during a run and each split shows both its own duration and the running total at that point.
Sources & methodology
Last updated .
Frequently asked questions
Does it keep accurate time in a background tab?
Yes. It measures elapsed time from your browser’s high-resolution clock rather than counting ticks, so the total stays accurate even if the tab is inactive.
What does the Lap button do?
It records a split without stopping the clock. Each lap shows both its own duration and the running total at that point.
Is my data stored?
No. The stopwatch runs locally in your browser and nothing is saved between visits.
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