How to use a stopwatch, step by step
Key takeaways
- Press Start (or Space) to count up from zero, and press it again to pause.
- Lap (or L) records a mark without stopping the clock; Reset clears the session.
- Paused time is never counted, so you can stop and resume as often as you need.
- Name the session, then copy the results, download a CSV or save the session on this device.
How do I start and stop the stopwatch?
- Open the stopwatch. It shows 00:00.00 and the word "Ready".
- Press Start or the Space bar. The display counts up.
- Press Pause or Space again to freeze the time. Press Start to carry on from the same point.
- Press Reset when you are done and want to begin a new measurement.
Space only works when you are not typing in a field or focused on another control, so a session name you are writing is never interrupted by a stray start.
What do the buttons do?
| Control | Key | What it does |
|---|---|---|
| Start / Pause | Space | Starts counting, or freezes the active time |
| Lap | L | Ends the current lap and starts the next one, while the clock keeps running |
| Reset | – | Sets the clock back to zero and clears unsaved laps |
| Open Full Screen | F | Fills the screen with the time; Escape leaves full screen |
| Show hundredths | – | Shows or hides the two digits after the seconds |
| Keep screen awake | – | Asks the browser to keep the screen on, where the browser supports it |
Hiding hundredths only changes the display. The stopwatch keeps measuring at the same precision underneath, so a lap recorded with hundredths hidden is just as exact.
How do I time several parts of one activity?
Use laps. Start the stopwatch at the beginning and press Lap each time one part ends, for example after each round of a quiz or each length of a pool. The table under the clock lists every lap with two numbers: the lap time (that part only) and the split time (everything since the start). After two laps you also see the fastest, slowest and average lap. Add a label to a lap if you want to remember what it was.
How do I keep my results?
- Copy results puts a short summary, with the total time, on your clipboard so you can paste it into a message or document.
- Download CSV gives a file you can open in a spreadsheet, with each lap's label, lap time, split time and the time in milliseconds.
- Save session stores the session on this device so it is still there next time. Pause first; you can keep up to 20 saved sessions and delete them whenever you like.
What happens if I reload the page or close the laptop?
A running stopwatch survives a reload in the same tab and picks up where it was. If your computer went to sleep or its clock was changed while timing, the stopwatch shows a warning and uses the larger of the two elapsed times it can work out. For anything important, keep the device awake and the tab open.
Questions
Can the stopwatch run for hours? Yes. It counts up to 999 hours, 59 minutes and 59.99 seconds.
Does the stopwatch count down? No, it only counts up. For a countdown with an alarm, use our sister site Online Timer.
Do I need an account? No. Everything works without signing up, and saved sessions stay on your own device.