Stopwatch
Professional Stopwatch
00:00:00.00
Stopwatch
Professional Stopwatch
Features
- Count-up stopwatch using performance.now() for high-resolution timing
- Start / stop / resume / reset controls
- Lap times with per-lap and cumulative display
- Display precision: 10 ms
- Runs entirely in your browser; tab state is local
How to use
- Enter your input data in the provided field.
- Configure any options as needed.
- View the results instantly and copy or download the output.
Tips & Best Practices
- Display refreshes every 10 ms — fine-grained enough for most user-facing timing.
- Background tabs throttle setInterval to 1 second. Keep the tab in focus or the displayed time will lag behind the actual elapsed.
- Lap times measure intervals between Lap presses; the cumulative column shows total elapsed at each lap.
- Reset clears all lap data — no confirmation. For "save" use the copy button on each lap.
- For precise timing (athletics / lab work) use a dedicated stopwatch device — browser timers can drift under system load.
FAQ
Is this tool free to use?
Yes, completely free with no registration, no limits, and no hidden costs.
Is my data private?
All processing happens in your browser. No data is ever sent to any server or third party.
Does it work offline?
Once loaded, the tool works entirely offline. All processing is done client-side with JavaScript.
Which browsers are supported?
Works in Chrome, Firefox, Safari, Edge, and all modern browsers on desktop and mobile.
Can I use the results commercially?
Yes, all output is yours to use freely in any personal or commercial project without restrictions.