Stopwatch
A precise stopwatch that shows time to the hundredth of a second. Start, stop, record laps and reset — all timed locally with your browser's high-resolution clock.
Laps
How to use the Stopwatch
Press Start to begin timing — the display updates in real time.
Press Lap at each checkpoint to record a split and the cumulative total.
Press Stop to freeze the time, or Reset to clear the timer and all laps.
Frequently asked questions
How accurate is the stopwatch?
It reads performance.now(), a high-resolution clock with sub-millisecond precision, and shows hundredths of a second. Real-world accuracy is limited only by your device’s timer resolution.
How do laps work?
Each time you press Lap the current elapsed time is recorded. The list shows the split for that lap plus the cumulative total since you started.
Does the stopwatch keep running if I switch tabs?
Yes. The elapsed time is calculated from timestamps rather than counted ticks, so it stays correct even if the browser throttles the page in the background.