Quick answer
An online stopwatch measures elapsed time from the moment you press Start. Press Lap at each checkpoint to record a lap time (that lap on its own) and a split time (the running total). Playxoft's free stopwatch shows hundredths of a second, highlights your fastest and slowest laps, compares the current lap with your best, exports laps as CSV and keeps counting through reloads because it reads your device clock.
- Hundredths of a second
- Lap and split times
- Fastest and slowest laps
- Live gap to best lap
- CSV export
- Survives reloads
- Fullscreen focus mode
- Keyboard shortcuts
How to use the Stopwatch
- 1Press Start or the Space key to begin timing.
- 2Press Lap (or L) at each checkpoint. The lap in progress and its gap to your best lap show under the digits.
- 3Press Stop to pause and Resume to carry on from the same time.
- 4Copy or download your laps as CSV for a spreadsheet, then press Reset (R) to start again.
Lap time vs split time: what is the difference?
Both are recorded each time you press Lap, but they answer different questions:
- Lap time is how long that lap took on its own, measured from the previous Lap press. Use it to compare laps with each other.
- Split time is the total elapsed time when you pressed Lap, measured from Start. Use it to track progress against a target finish.
Three laps of a 1,200 m run might look like this:
| Lap | Lap time | Split time |
|---|---|---|
| 1 | 01:32.40 | 01:32.40 |
| 2 | 01:35.10 | 03:07.50 |
| 3 | 01:29.85 | 04:37.35 |
Lap 3 is the fastest and lap 2 the slowest; the stopwatch highlights both automatically and shows the average lap time above the table.
How accurate is an online stopwatch?
The timing itself is precise to the millisecond. This stopwatch does not add up ticks; it records the moment you pressed Start and subtracts it from your device clock whenever it draws, so busy pages, background tabs and slow phones cannot make it drift. The display shows hundredths of a second, and the full milliseconds are kept in the CSV export.
In practice the biggest source of error is the human pressing the button. Reaction time is typically about 0.2 to 0.3 seconds, and it varies from press to press. To keep your laps comparable:
- Press at the same visual cue every lap, such as a line on the track or the wall in a pool.
- Use the L key or the big Lap button rather than a small target.
- For official races, electronic timing gates are the standard. A hand-held stopwatch is great for training, not for records.
Timing laps for running, swimming and training
On a phone, turn on Keep screen awake so the screen does not lock between laps, and use Focus mode for huge digits and two thumb-sized buttons. Under the digits you will see the current lap and its gap to your best lap: green means you are on pace or ahead, gray means you are behind.
The stopwatch keeps running if you switch apps or reload the page, because the start time is saved in your browser. Up to 999 laps are stored per session.
Training in fixed blocks instead? The interval timer beeps you through work and rest phases, and the countdown timer is better for a set duration such as a 20-minute tempo run.
Exporting laps to a spreadsheet
Copy or Download gives you comma-separated values that open directly in Excel, Google Sheets or Numbers. Each row has the formatted times plus raw milliseconds, so you can chart or average them without parsing:
Lap,Lap time,Split time,Lap (ms),Split (ms)
1,01:32.40,01:32.40,92400,92400
2,01:35.10,03:07.50,95100,187500
3,01:29.85,04:37.35,89850,277350Nothing is uploaded: the file is built in your browser.
Stopwatch keyboard shortcuts
| Key | What it does |
|---|---|
| Space | Start or stop |
| L | Record a lap |
| R | Reset (when stopped) |
| F | Focus mode (fullscreen) |
| Esc | Leave focus mode |
Single-key shortcuts can be switched off in the keyboard menu if they clash with a screen reader or other tools.
Frequently asked questions
Last updated by the Playxoft engineering team.