Online Tool Store
Stopwatch
Time anything with a precise stopwatch that tracks lap times, right in your browser — highlights your fastest and slowest laps. Nothing is uploaded.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
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Lap times will appear here once you start and click Lap.
How it works
- Click Start to begin timing.
- Click Lap at any point to record a split — each lap shows its own time and the running total.
- Click Pause to stop the clock without losing your time, or Reset (once paused) to clear everything and start over.
Each lap's time is the difference between the current total elapsed time and the total at the previous lap — so the lap times always add up to the overall elapsed time shown at the top.
FAQ
Does anything about my timing get sent anywhere?
No. It runs entirely on your device using your browser's own high-precision clock — nothing is uploaded or logged.
How precise is it, really?
It's accurate to the hundredth of a second (centiseconds) and reads from the browser's high-resolution performance clock, not the regular system clock — the same source browsers use for measuring page performance, which doesn't drift the way a wall clock can.
Does it keep running if I switch to another tab?
Yes — the elapsed time is tracked from real timestamps, not by counting ticks, so switching tabs (which browsers slow down to save power) doesn't throw off the total. It needs the tab to stay open, though; closing it stops everything.
What do the colored lap times mean?
Once you've recorded at least three laps, your fastest lap is highlighted in green and your slowest in red, so you can spot your best and worst splits at a glance.
Why can't I reset while it's running?
Pause it first — this avoids accidentally wiping a timing run with a stray click while it's still counting.
How we compare
| Feature | Online Tool Store | Phone stopwatch app | Physical stopwatch |
|---|---|---|---|
| No file upload — runs in your browser | ✓ | ✓ | N/A — physical device |
| No install, works on any device with a browser | ✓ | Built in, but phone-only | You have to own and carry one |
| Highlights your fastest and slowest lap automatically | ✓ | Varies | You compare by eye |
Your phone's built-in stopwatch is perfectly capable too, but it means picking up your phone. If you're already at a computer, Stopwatch is right in the same tab you're working in, with fastest/slowest laps called out automatically.