Stopwatch
Stopwatch with lap times.
Stopwatch at a glance
Stopwatch is a free online app you can use right now to stopwatch with lap times โ no account, no install and no usage limit. It runs entirely inside your browser, so whatever you enter stays on your own device.
- Price
- Free โ no trial, no paid tier, no watermark
- Sign-up
- Not required
- Where it runs
- In your browser โ nothing is uploaded to a server
- Works on
- Chrome, Safari, Firefox and Edge โ desktop, tablet and phone
- Category
- Productivity
About Stopwatch
Start, stop and reset a stopwatch, recording lap times as you go.
The distinction between lap and split time is worth knowing because they answer different questions. A lap time is the duration of one segment measured from the previous lap marker. A split is the total elapsed time at that point. Running four laps of 60, 62, 61 and 63 seconds gives splits of 60, 122, 183 and 246 โ the laps show consistency, the splits show cumulative pace. Most stopwatches record both, and mixing them up makes performance look very different from reality.
Timing runs in your browser using a high-resolution clock, which is accurate to well under a millisecond in principle. The practical limit is not the clock but you: human reaction time is roughly 200-250 milliseconds, so any manually started and stopped measurement carries far more error from the operator than from the timer. For anything where hundredths genuinely matter, automated triggering is the only reliable approach.
Browsers throttle timers in background tabs to save power, so a stopwatch left running behind other windows may display less smoothly. The elapsed time remains correct because it is calculated from timestamps rather than counted frames.
How to use Stopwatch
- Press start to begin timing.
- Record laps as you go โ each shows both the lap duration and total elapsed time.
- Stop when finished, and reset to clear.
Frequently asked questions
What is the difference between lap and split time?
A lap is the duration of one segment since the last marker. A split is the total elapsed time at that point. Four 60-second laps give splits of 60, 120, 180 and 240 โ laps show consistency, splits show cumulative pace.
How accurate is it?
The underlying clock is accurate to well under a millisecond. The real limit is human reaction time, roughly 200-250 milliseconds, which dominates any manually started measurement. For precision timing you need automated triggering.
Does it keep running in a background tab?
Yes. Browsers throttle background tabs so the display may update less smoothly, but elapsed time is calculated from timestamps and stays correct.
Will I lose my time if the page reloads?
Yes โ reloading resets the stopwatch. Note important lap times elsewhere if you are timing something you cannot repeat.