00:00:00.000
Space = Start/Stop · L = Lap · R = Reset
Laps (0)
#
Lap time
Total time
Uses for an Online Stopwatch
Also searched as: stopwatch online free | online stopwatch with laps | lap timer online | split time stopwatch
A stopwatch is one of the most versatile productivity and sports tools. Use it for interval training, cooking timers, Pomodoro sessions, speech practice, game timing, and scientific experiments. This tool runs entirely in your browser with millisecond precision using the Performance API.
Use the Online Stopwatch above — enter your values and get instant results. This free online tool calculates stopwatch online free with laps without any download or signup required. Results update in real time as you type.
Use the Online Stopwatch above — enter your values and get instant results. This free online tool calculates online stopwatch for sports without any download or signup required. Results update in real time as you type.
This stopwatch uses performance.now() for timing, which provides sub-millisecond precision and is not affected by system clock adjustments. The display updates every 10ms. Accuracy is limited by JavaScript event loop jitter (typically ±1–5ms) and browser tab throttling (background tabs may update less frequently). For casual use, timing accuracy is effectively identical to a physical stopwatch. For precision sports timing within 10ms, use dedicated hardware timing equipment.
Yes — the timer keeps running because it uses timestamps rather than counting intervals. When you switch back, the display catches up to the current elapsed time. However, the display update rate may slow in background tabs (browsers throttle background timers to save battery). The elapsed time calculation is always accurate — only the visual update frequency may vary. For precise lap timing, keep the tab visible or use Picture-in-Picture mode if your browser supports it.
Lap time is the time for each individual segment between presses of the lap button. Split time (also called cumulative time) is the total elapsed time at the moment the lap button is pressed. If laps are 0:30, 0:28, 0:32 then splits are 0:30, 0:58, 1:30. This tool shows both: the individual lap column shows lap times, the total time column shows splits. Athletes use split times to track overall pace and lap times to compare individual intervals.
This tool can record hundreds of laps limited only by your browser's memory. Laps are stored in JavaScript memory for the current session and are lost when you close the tab (export CSV first if you need to save them). The best and worst laps are highlighted in green and red for quick comparison. For marathon lap tracking (cycling, running long events), export periodically to preserve your data.
Yes — press Lap at the end of each work interval and rest interval to track both separately. The lap list will show alternating work and rest periods. For structured interval training with automatic alerts at fixed intervals, the Pomodoro Timer tool on this site is better suited — it automatically switches between work and break phases and plays audio alerts. Use the stopwatch for free-form timing where intervals vary or when you want to measure actual vs planned times.