Precision stopwatch with lap and split times, keyboard shortcuts and millisecond accuracy. Free and runs in your browser.

Precise, timestamp-based timing that stays accurate even in a background tab. Nothing is uploaded — it runs entirely in your browser.

Ready
00:00:00.00
SpaceStart / pause LLap RReset
Laps 0
# Lap time Total
No laps yet — hit Lap while running.

About Online Stopwatch

The online stopwatch measures elapsed time with millisecond precision, with lap and split recording built in. Press Lap while running to capture each segment; the table shows every lap time and running total, and flags your fastest and slowest laps automatically.

Because timing is timestamp-based — elapsed time is derived from the system clock, not from counting intervals — it stays accurate even in a background tab, where browsers throttle ordinary timers. A keyboard shortcut (Space to start and pause) keeps your hands off the mouse during timing.

You can copy the full lap table to the clipboard for a training log or spreadsheet. Everything runs locally in your browser, free, with nothing uploaded.

How to use Online Stopwatch

  1. Press Start — or hit the Space key — to begin timing.
  2. Press Lap to record a split each time a lap completes.
  3. Pause and resume as needed; the elapsed time picks up exactly where it stopped.
  4. Review the lap table with fastest and slowest laps highlighted, and copy the laps if you want to keep them.
  5. Press Reset to clear the time and laps for the next session.

Frequently asked questions

Yes. It computes elapsed time from timestamps rather than accumulating timer ticks, so browser throttling of background tabs does not cause drift — the reading is correct whenever you return.

A lap time is the duration of one segment since the previous lap press; the split (total) is the overall elapsed time at that moment. The table records both for every lap.

Yes — press Space to start and pause without touching the mouse, which makes hand-timing much more precise. On-screen buttons cover lap, reset and resume.

Use the Copy laps button to place the whole table on your clipboard, ready to paste into a spreadsheet, a message or your training log.

The readout shows milliseconds and is driven by the system clock. Human reaction time (about 0.2 s) is the practical limit for hand timing, but the stopwatch itself measures far finer.

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