Quick answer. Press Start (or the space bar) to begin, Lap (or L) to record a lap, Stop to pause and Reset (or R) to clear. Download your laps as CSV when you are done.
How to use the online stopwatch
- Start. Press Start or the space bar. The display counts minutes, seconds and hundredths; hours appear after the first hour.
- Record laps. Press Lap or L each time a runner passes the line, a swimmer touches the wall or a task step ends. The newest lap appears at the top.
- Stop and resume. Stop freezes the time. Press Resume to carry on from the same point; paused time is not counted.
- Export. Download laps as a CSV file and open it in Excel, Google Sheets or Numbers.
- Reset clears the time and all laps so you can start fresh.
Lap time vs total time (splits)
Each row in the lap table has two numbers. Lap time is how long that single lap took, from the previous lap press to this one. Total is the elapsed time since you started, which many coaches call the split or cumulative time. Adding up all the lap times always gives the latest total.
| Lap | Lap time | Total |
|---|---|---|
| 1 | 01:32.40 | 01:32.40 |
| 2 | 01:28.15 (best) | 03:00.55 |
| 3 | 01:35.90 (slowest) | 04:36.45 |
Once you have two or more laps, the fastest lap is shown in green and the slowest in red, with the average lap time underneath. It is a quick way to see whether you are pacing evenly or fading at the end.
What people time with it
- Running and swimming laps on a track or in a pool, and interval training.
- Speeches and presentations: rehearse and see how long each section takes.
- Work studies: time how long it takes to pack an order or finish a task, then use the CSV to work out an average. Pair it with our hourly rate calculator to price your time.
- Science experiments, cooking and games where you need more precision than a phone clock.
How accurate is it?
The stopwatch reads performance.now(), a high-resolution clock that only moves forward and is not affected if your computer adjusts its clock. Instead of adding up screen refreshes, it stores the start moment and calculates the elapsed time on every frame, so it does not drift, even over hours or when the tab is in the background. The display shows hundredths of a second, cut off rather than rounded, the same as a handheld sports stopwatch. In practice the limit is your own reaction time on the button, which is usually 0.15 to 0.25 seconds.
Keep the page open while timing. Reloading or closing the tab resets the stopwatch, and laps are not saved anywhere, so export the CSV first.
Frequently asked questions
Is this online stopwatch free?
Yes. It is free, with no sign-up and no limit on laps or time.
Does the stopwatch keep running in another tab?
Yes. Time is measured from the start moment with a high-resolution clock, so it stays correct in the background. The display catches up as soon as you return.
What is the difference between lap time and split time?
Lap time is the length of one lap. Total, also called split or cumulative time, is the time since you pressed Start. The lap times always add up to the latest total.
What keyboard shortcuts can I use?
Space starts and stops, L records a lap and R resets. Shortcuts work whenever you are not typing in a text box.
How do I export my laps?
Press Download laps (CSV). The file has the lap number, lap time, total time and the same values in milliseconds for spreadsheets.
How precise is the timing?
The display shows hundredths of a second and the clock underneath is precise to well under a millisecond. Your reaction time on the button matters far more.
Are my times saved?
No. Nothing is uploaded or stored. Reloading the page clears the stopwatch, so download the CSV first if you need a record.