A precise online stopwatch with lap times
Whether you're timing a run, a swim, a presentation, a science experiment or a speed-cubing attempt, this online stopwatch gives you accurate timing to the hundredth of a second right in your browser. Record as many laps as you need, see your fastest and slowest laps at a glance, and download the results. It works on desktop and mobile and needs no app.
Features
- Hundredths of a second display with large, easy-to-read digits.
- Unlimited laps with lap time and total (split) time for each.
- Fastest and slowest laps highlighted automatically.
- Keyboard shortcuts — Space to start and stop, L for a lap, R to reset.
- Pause and resume without losing time.
- CSV export of all laps for spreadsheets and training logs.
- Accurate in background tabs, using the browser's monotonic high-resolution clock.
Common uses
- Running, swimming and cycling — record each lap or interval and compare your pace.
- Interval training — time work and rest periods.
- Speeches and presentations — rehearse and check how long each section takes.
- Cooking and brewing — measure steeping, proofing and resting times.
- Lab and classroom experiments — time reactions, pendulums or falling objects.
- Productivity — track how long tasks really take compared to your estimates.
- Games and puzzles — time Rubik's cube solves, quizzes and challenges.
Lap time vs. split time
Coaches and athletes use two kinds of measurement:
- Lap time — the duration of a single lap or segment, useful for checking whether your pace is steady.
- Split (total) time — the cumulative time from the start, useful for checking whether you're on target for a goal time.
For example, if you run four laps in 1:52, 1:55, 1:50 and 1:48, your splits are 1:52, 3:47, 5:37 and 7:25. Steadily falling lap times — a "negative split" — show you finished strong.
Getting the most accurate time
Human reaction time adds a small delay to every manual timing. To reduce it, watch for the start signal rather than the screen, use the keyboard instead of a mouse or touchscreen, and use the same method every time so your measurements are consistent with each other.
Need to count down instead of up? Use the Countdown Timer, which plays an alarm when time runs out.