Uses performance.now() for sub-millisecond precision and requestAnimationFrame for smooth display.

Records lap time (since previous lap) and split time (total elapsed).

Keeps time across tabs?

Yes. Elapsed time calculated from real timestamps, no skip or double-count.

What precision is shown?

Hundredths of a second, as mm:ss.cc, switching to hh:mm:ss.cc once an hour has passed.

No. Elapsed time and the lap list live in the page only, so a reload or a Reset clears them. Copy the times you need before leaving.

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How accurate?: Uses performance.now() for sub-millisecond precision and requestAnimationFrame for smooth display.
Lap button?: Records lap time (since previous lap) and split time (total elapsed).
Keeps time across tabs?: Yes. Elapsed time calculated from real timestamps, no skip or double-count.
What precision is shown?: Hundredths of a second, as mm:ss.cc, switching to hh:mm:ss.cc once an hour has passed.
Are laps kept if I reload?: No. Elapsed time and the lap list live in the page only, so a reload or a Reset clears them. Copy the times you need before leaving.