A free online stopwatch accurate to a hundredth of a second. Record laps, see fastest and slowest splits, and control it from the keyboard.
A stopwatch measures elapsed time from the moment you start it — for laps, drills, cooking, billing, timing how long a build actually takes. This one reads to a hundredth of a second and records splits without stopping the clock.
It also takes keyboard input, which matters when your hands are busy or the screen is across the room: space starts and stops, L records a lap, R resets.
The lap table shows two columns that are easy to confuse. Split is the time for that lap alone — the gap since the previous lap. Total is the elapsed time from the start to the moment you pressed Lap. For even pacing, watch the split column; for pace against a target, watch the total.
Once you have at least two laps, the fastest and slowest are marked, and a summary shows fastest, slowest, average and overall total. The average is the mean of your splits, which is the number to compare between sessions.
Elapsed time is measured against the system clock and displayed to a hundredth of a second, and the maths is exact. Your reaction time is not: a hand-pressed start and stop carries roughly 100 to 300 milliseconds of human error at each end. The displayed hundredths are real, but treat the last digit as precision rather than accuracy, and do not use a hand-timed stopwatch to settle results that are within a tenth of each other.
Timing is calculated from the clock rather than by counting ticks, so switching tabs or letting the machine idle will not make it drift. Browsers do throttle background tabs, so a countdown may repaint less often while hidden, but the elapsed time it reports when you come back is still correct.
Nothing you enter is sent anywhere. This page has no backend and no account — your settings, alarms and saved entries are stored in your own browser's local storage and stay on this device. Clearing your browser data clears them.
Space starts and stops, L records a lap, R resets. They are ignored while you are typing in a text field, so they will not fire by accident.
No. Stopping banks the elapsed time and Resume continues from that total, so you can stop and start as many times as you need without losing the accumulated time.
No. The stopwatch and its laps are deliberately session-only — a reload starts clean. Note anything you need to keep before reloading.
Split is the duration of that single lap. Total is the elapsed time from the start of the run up to that lap. Four 30-second laps show splits of 0:30 each and totals of 0:30, 1:00, 1:30 and 2:00.
Yes. Elapsed time comes from the clock rather than a tick counter, so the total is correct even if the display refreshes less often while the tab is hidden.