Stopwatch
Online stopwatch with 1/100-second precision: start, pause, reset and lap recording, showing per-lap and cumulative times at a glance. Great for sports training, cooking and productivity timing.
How to use
- Click "Start" to begin — the big digits tick in real time with 1/100-second precision. Click the same button again to "Pause".
- While running, click "Lap" any time to record the current split. The lap list shows both the per-lap time and the cumulative time.
- "Reset" stops the watch and clears the time and all laps. You can also reset while paused.
- The browser tab title shows the running time, and accuracy is based on timestamp differences, so switching tabs never makes the watch drift.
FAQ
How accurate is it? Does it slow down over time?
Time is computed from system timestamp differences and only displayed by a periodic refresh, so even if the browser throttles timers or the tab goes to the background, the accumulated time stays accurate — no classic setInterval drift.
What is the difference between Lap and Reset?
Lap records the current split and keeps the watch running — ideal for pacing each segment (for example, per-kilometer time). Reset stops the watch and clears both the total time and every recorded lap so you can start over.
How many laps can I record?
There is no limit. Laps are listed in order, each row showing the split time and the cumulative time up to that lap, so you can compare segments easily.
Is my timing data uploaded anywhere?
No. All timing and lap calculations happen locally in your browser — there are no network requests and everything disappears when you close the page.