Online stopwatch
Start, stop and lap, to a hundredth of a second
Press Start to begin timing. Press Lap while it runs to record split times.
Ready. Press Start.
Laps
No laps yet.
| Lap | Lap time | Total |
|---|
Using the stopwatch
Start begins timing and the same button then becomes Stop. Press Start again and it carries on from where it stopped. Reset clears the time and all the laps.
Laps
Press Lap while the stopwatch is running to record a split. Each row shows the time for that lap alone and the total elapsed at that moment, with the newest lap at the top. Once there are two or more laps, the fastest and slowest are labeled.
How the time is kept
The display shows minutes, seconds and hundredths of a second, and adds hours after 60 minutes. The elapsed time is read from your device's clock each time the screen redraws, so the total does not depend on how smoothly the page is updating. If you switch to another tab the display stops redrawing, but the time keeps running and is correct when you come back. The tab title shows the elapsed time to the second.
How precise is it?
Hundredths are shown, but your finger adds more error than the clock does: human reaction time is typically one to three tenths of a second at each press. That is fine for laps in training, cooking, presentations and practice, but not for official race timing. Because it follows the device clock, a manual clock change while it runs would throw the reading off.
Keyboard and saving
The buttons are ordinary buttons: Tab to one and press Space or Enter. Nothing is saved, so reloading or closing the page clears the laps. Write them down first.