Stopwatch
Time anything, with lap splits and a running total.
Elapsed time
Laps
Private by design. This page has no backend. Timing happens in your browser using high-resolution timestamps.
How the stopwatch works
The stopwatch records a start timestamp and computes elapsed time on each display tick. This means the timer stays accurate even if the browser tab is throttled while you switch away, because it always measures the real time gap rather than counting ticks.
Lap splits
Press Lap while the stopwatch is running to record a split. Each lap shows the total elapsed time at that point and the delta since the previous lap (or since the start for the first lap). Laps are appended with DOM text methods — no user input is ever placed through innerHTML.
How to use the Stopwatch
- Press start to begin timing.
- Press lap to record split times as you go.
- Press stop, then reset to clear.
Frequently asked questions
How precise is the stopwatch?
It shows elapsed time to hundredths of a second in hours, minutes and seconds.
Can I record more than one lap?
Yes. Each lap is listed with its split and the running total.
Does it keep time if I leave the page?
The stopwatch uses real time, so elapsed time stays correct while the tab is in the background.