Online Stopwatch
Time anything from a sprint to a meeting with a stopwatch that shows hours, minutes, seconds and milliseconds. Record laps, see your fastest and slowest, and download the lap times.
Ready
Time is measured from the moment you press Start, so the stopwatch stays accurate when you switch tabs or the screen updates less often. The display shows hours, minutes, seconds and milliseconds.
Press Lap while the stopwatch is running to record split times.
How to Use the Online Stopwatch
- Press Start to begin timing.
- Press Lap to record a split without stopping the clock. Each lap shows its own time and the running total.
- Press Pause to stop the clock and Resume to continue from the same time.
- Copy the lap list or download it as a CSV file, then press Reset to start again.
Example
Three running laps
- Input
- Start → Lap → Lap → Lap
- Output
- Lap 1 00:01:32.410 total 00:01:32.410 Lap 2 00:01:29.880 total 00:03:02.290 Lap 3 00:01:35.025 total 00:04:37.315 Lap 2 is marked Fastest and lap 3 Slowest.
About the Online Stopwatch
An online stopwatch is handy whenever you need to measure how long something takes: running laps, swimming lengths, speeches, cooking steps, reaction tests, or how long a task really takes compared with your estimate.
Elapsed time is calculated from high-resolution timestamps rather than by adding up ticks, so the stopwatch does not drift. If you switch tabs or your phone dims the screen, the display may stop updating for a while, but the correct time appears as soon as you return.
Lap times are measured at the moment you press Lap. Once you have three or more laps, the fastest and slowest are labelled. The display shows milliseconds, but real-world accuracy also depends on your reaction time and how quickly your device responds to a tap, which is usually a few tens of milliseconds.
Everything runs in your browser. Closing or reloading the page clears the stopwatch and laps, so copy or download your laps first.
Frequently Asked Questions
Does the stopwatch keep running in the background?
Yes. Time is measured from when you pressed Start, so switching tabs, minimising the browser or locking a desktop screen does not affect the result. The display updates again when you come back.
How accurate is the stopwatch?
The timing itself is accurate to well under a millisecond. In practice, the limit is how quickly you press the button and your device registers the tap, so treat the last digits as approximate for hand-timed events.
Can I save my lap times?
Yes. Use Copy to copy the laps as text, or Download CSV to save a file you can open in Excel, Google Sheets or Numbers.
Can I use the stopwatch with a keyboard?
Yes. Press Tab to move between the Start or Pause, Lap and Reset buttons, and press Enter or Space to use them.
What is the difference between lap time and total time?
Lap time is how long that lap took, measured from the previous lap. Total time is the time on the stopwatch when you pressed Lap.
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