Stopwatch
A timestamp-accurate online stopwatch with start, stop, lap, and reset, plus a lap table with splits and totals.
Processed locally in your browser — nothing is uploaded.
About Stopwatch
Start, stop, lap, and reset with a display precise to hundredths of a second. Time is measured from system timestamps rather than by counting screen updates, so the reading stays accurate even when the tab is throttled in the background.
Each lap records both its split (time since the previous lap) and the running total.
Common uses
- Time workouts, intervals, and rest periods
- Track how long tasks actually take
- Record lap splits for practice runs
Example
Input
Lap pressed at 01:00.00 and 02:30.00
Output
Lap 2 — split 01:30.00, total 02:30.00