Stopwatch
Online stopwatch with lap tracking. Start, pause, and record lap splits — all in your browser. No install needed. Accurate to milliseconds for timing tasks, workouts, or experiments.
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How to use the stopwatch
Start the stopwatch, click Lap to record split times, Reset to zero everything out.
Formula & explanation
Uses Date.now() differences for accuracy independent of CPU jitter; redraws every ~31 ms.
Examples
Track workout intervals, kitchen timers, or anything you'd time on a phone.
Frequently asked questions
- How accurate is the stopwatch?
- It uses Date.now() sampled every ~31 ms, so displayed precision is to the centisecond (1/100 s). Actual accuracy depends on tab-throttling — background tabs may drift by tens of milliseconds.
- How many laps can I record?
- There's no hard limit. Laps are stored in memory so they're cleared when you reset or refresh the page.
- Does pausing the stopwatch lose time?
- No — pausing captures the elapsed time, and resuming continues from exactly where it left off.
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