Online Stopwatch
Start, pause, lap, and reset — accurate to the centisecond.
About Online Stopwatch
Online Stopwatch is a precise timer with start, pause, resume, lap, and reset, displaying hundredths of a second (the display updates ~30 times a second; the underlying time is exact to the millisecond since it's derived from timestamps). It is the right tool for timing anything — a workout interval, a cooking step, a code build, a kid's race in the yard — where you want lap times alongside the running total without installing an app or pulling out a phone.
Worked example: start the stopwatch, hit 'Lap' three times during a workout to record the splits, hit 'Pause' when the activity ends. The lap list shows each split time (the time between successive lap presses) and the running total (the time from start to that lap), so you can see whether a session is consistent across rounds. 'Reset' clears the laps and returns the clock to 00:00.00 for the next run.
Two notes on accuracy. The display updates several times a second (centisecond resolution) but the underlying timing is millisecond-based and timestamp-derived — the elapsed time is recomputed from the wall clock on every tick, not by incrementing a counter. That keeps the stopwatch accurate even if you switch tabs and the browser throttles background JavaScript; when you return, the time shown is correct rather than having drifted by however long the tab was inactive. The catch: the stopwatch needs the page open to be visible, and closing the tab clears the lap list (laps are not persisted).
All timing runs in your browser. Nothing is uploaded.