Free Online Stopwatch
A precise online stopwatch that counts up in hundredths of a second. Start, pause, resume, and record lap times — all in your browser with no download or sign-up.
Counting down rather than up? The Countdown Timer does that, and the Timecard Calculator turns elapsed time into hours worked.
How to use the Stopwatch
- 1 Press start to begin timing.
- 2 Press lap to record a split without stopping the clock — useful for laps or intervals.
- 3 Read the lap list, which shows each split and the running total.
- 4 Press stop to pause, then reset to clear.
How to Use
Click Start to begin timing. Click Lap to record an intermediate split, and Pause to stop. Use Reset to clear the timer and laps. You can also press the space bar to start or pause.
- Hundredths-of-a-second precision
- Unlimited lap / split times
- Keyboard shortcut: space to start or pause
- Runs on requestAnimationFrame for smooth, accurate display
Accuracy note
This stopwatch measures elapsed time using the high-resolution performance.now() clock, so it stays accurate even if the display briefly stutters. Browsers may throttle background tabs, so for critical timing keep this tab in the foreground.
Frequently asked questions
How accurate is it?
It reads the high-resolution performance clock, which measures in fractions of a millisecond, rather than a wall-clock date. That makes it far more precise than a phone stopwatch app that samples only a few times a second, though it still depends on how fast the display can repaint.
What is the difference between lap and split time?
A lap is the time for the section you just completed, while the split is the cumulative total since you started. Both are recorded together, so you can see whether you slowed down without doing any arithmetic.
Does it keep timing if I switch tabs?
The elapsed time stays correct, because it is calculated from timestamps rather than counted ticks. However, browsers throttle background timers, so the display may update less often while the tab is hidden and catch up when you return — the total remains accurate.
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