Start, stop, lap and reset
Start begins timing from the current value, so stopping and starting again accumulates time rather than restarting it. Lap adds a row showing both the split — the time since the previous lap — and the total elapsed time, which is what runners and coaches actually compare. Reset clears the clock and the lap list together.
Once you are done here, the pomodoro timer picks up where this leaves off.
Reading centiseconds
The display uses MM:SS.CC, where the final pair of digits is hundredths of a second. That resolution is plenty for sprint splits, lab experiments and cooking, but remember that human reaction time is roughly 0.2 s — for anything closer than that, electronic timing gates beat a thumb on a button.
Stopwatch or countdown?
A stopwatch counts up from zero and answers "how long did that take?". A countdown counts down and answers "how long is left?". If you need the second one, set any duration with the countdown timer, or use a preset such as the 10 minute timer.
Frequently asked questions
- How many laps can I record?
- As many as you like. Each lap appears at the top of the list with its split time and the total elapsed time, and the list scrolls as it grows.
- Does Stop erase the time?
- No. Stop holds the current value on screen and pressing Start again continues from there. Only Reset returns the stopwatch to zero.
- How accurate is the online stopwatch?
- It reads the system clock, so the measurement itself is accurate to a few milliseconds. The practical limit is your own reaction time when pressing the buttons.
- Does it save my laps?
- No. Nothing is stored or uploaded — reloading the page clears the stopwatch and the lap list completely.
- Can I use it to time something longer than an hour?
- Yes. The clock keeps counting past 60 minutes and simply rolls the minute figure onwards, so a long session still records correctly. Just leave the tab open, because the timing lives in the page and reloading clears it.