Online Stopwatch

Online Stopwatch times anything from a few seconds to many hours, to the hundredth of a second, with laps. Press Start, then Lap each time a runner passes, a question is answered or a step is done: every lap shows its own time and the running total, newest first, and once there are three or more the fastest and slowest are marked. Unlike stopwatches that count ticks, this one keeps time from the clock — it remembers the moment it started — so a tab in the background, a laptop that went to sleep or a page you reload still reads the right time when you come back. The elapsed time shows in the tab title while it runs. Keyboard shortcuts make it quick to use without looking: Space starts and pauses, L records a lap, R resets. The laps can be downloaded as a CSV file for a spreadsheet.

1. Press Start (or Space).
2. Press Lap (or L) at each split.
3. Press Pause to stop; Resume carries on; Reset clears it when paused.
4. Download the laps as CSV if you need them later.

• Accuracy is that of your device’s clock — far better than a hundredth of a second over an hour — but your reaction time when pressing the button is the real limit, about a fifth of a second.
• Displayed hundredths update about 25 times a second; the recorded time is exact to the millisecond.
• Keyboard shortcuts work when no button or field has focus, so pressing Space on a focused button does not count twice.
• Up to 500 laps are kept.
• Everything runs in your browser. The running time and laps are kept on this device only, so a reload carries on; Reset or Delete everything on Your data clears them.

Yes. It records when it started, so the time is right whenever you look, even after the tab was in the background or the computer slept.

It carries on: the start time and laps are kept on this device, so the stopwatch reads the same total after the reload.

A lap time is the time for one lap alone; a split (the total column) is the time from the start to that lap.

Yes: Space to start or pause, L for a lap, R to reset when paused.