Stopwatch
Precise stopwatch with laps and keyboard shortcuts.
- Instant
- Free
- Private (processed locally)
- No sign-up
A stopwatch that doesn’t lose a fraction of a second
For interval sets, a cake in the oven or a rehearsal run, this stopwatch shows the hundredth of a second and keeps all your laps. The buttons are there, but the real pros use the keyboard: Space, L, R.
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Start
Button or Space bar — the clock starts to the hundredth.
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Mark your laps
Lap button or the L key: every lap is timestamped.
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Analyse
Best lap in green, worst in red, total time on the right.
Keyboard shortcuts
| Key | Action |
|---|---|
| Space | Start / pause |
| L | Record a lap |
| R | Reset |
Time is computed from the browser’s high-resolution clock: it stays exact even if the display freezes in a background tab. Everything works offline, nothing is sent.
Frequently asked questions
How accurate is the stopwatch?
The display goes down to the hundredth of a second and relies on the browser’s high-resolution clock (performance.now), immune to system clock changes. For official timing, dedicated hardware is still required.
What are the keyboard shortcuts?
Space starts or pauses, L records a lap, R resets. They work whenever you are not typing in a field — handy for timing without taking your eyes off the screen.
What are the best and worst laps for?
Across a series of laps, the fastest is highlighted green and the slowest red. It is the key info in interval work (running, swimming) to see whether your efforts stay even or you fade.
Does the stopwatch keep running if I switch tabs?
Elapsed time stays exact because it is computed from timestamp differences, not frame counting. The display may freeze in a background tab, but it corrects itself instantly on return.