Time anything in your browser with start, pause, resume, reset and a list of lap times.
Example
Just under a minute reads 00:00:59.999, and an hour and a half plus half a second reads 01:30:00.500. Hours keep counting past 24, so a long session shows 25:01:01.000.
Calculation method
Timing uses the browser’s high-resolution clock, which measures intervals accurately even if the device clock is adjusted. Elapsed time adds the intervals already recorded to the one currently running, so pausing and resuming never loses or double-counts a stretch.
Important notes
The displayed milliseconds are limited by how quickly you can press a button, which typically adds a reaction delay of around two tenths of a second, and by the screen refresh rate. For sports events that need official results, use certified timing equipment.
Start, pause, resume and reset
Press Start to begin timing and the display shows hours, minutes, seconds and milliseconds. Pause stops the clock without losing the elapsed time, and Resume continues from the same point, so you can time only the active parts of an activity. Reset clears the time and every lap. Just under a minute appears as 00:00:59.999, and an hour and a half plus half a second appears as 01:30:00.500. Hours keep counting past 24, so 25 hours, 1 minute and 1 second shows 25:01:01.000.
Recording laps
Press Lap while the stopwatch runs, or while it is paused after some time has been recorded, to add the current time to the list. The newest lap appears at the top. Each lap is the total elapsed time at that moment, not the time since the previous lap, so subtract consecutive entries to find individual lap times: if two laps read 00:01:12.300 and 00:02:20.800, the second lap took 1 minute 8.5 seconds. Laps are cleared when you reset or reload the page.
How precise the numbers are
Timing uses the browser’s high-resolution clock, which measures intervals accurately even if the device clock is adjusted. The displayed milliseconds are still limited by how quickly you can press a button, which typically adds a reaction delay of around two tenths of a second, and by screen refresh. Switching tabs does not stop the stopwatch, although the display may update less often until you return. For sports events that require official results, use certified timing equipment.
Worked examples| Input | Result |
|---|
59,999 ms | 00:00:59.999 |
5,400,500 ms | 01:30:00.500 |
86,399,999 ms | 23:59:59.999 |
90,061,000 ms | 25:01:01.000 |