Online Stopwatch
A stopwatch accurate to a hundredth of a second, with lap and split times. Start it with the spacebar and export your results as CSV.
Space: start / pause — L: lap — R: reset
A reliable stopwatch, free of distractions
This stopwatch shows time to the hundredth of a second and runs straight in your browser, with no download and no account. It works just as well for sports training as for lab measurements, speaking times or cooking.
Time is derived from the system clock rather than counted up step by step: even if you switch tabs and the browser throttles background scripts, the stopwatch stays accurate to the millisecond.
How to use it
- Press Start, or hit the spacebar, to launch the stopwatch.
- Click Lap (or press L) at each split: both the lap time and the total elapsed time are recorded.
- Export the lap list as CSV to keep it or analyse it in a spreadsheet.
Frequently asked questions
Yes. Time is read from the system clock, so even if the browser puts the tab to sleep, the value you see when you come back is correct. The remaining time also appears in the tab title.
The display goes down to a hundredth of a second. Actual accuracy depends on your device clock and on your reaction time when clicking, which is the real limiting factor for manual timing.
It records a split time without stopping the stopwatch. Each lap shows its own duration and the total elapsed time; the fastest and slowest laps are highlighted.
No, laps are not kept once the page is closed. Use the CSV export before you leave if you want to keep your measurements.
