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Randozi

Online Stopwatch

Start, stop and record laps — the time keeps running correctly even if you switch tabs.

Ready

00:00.00

Tip: press the space bar to start and stop.

How it works

  1. Press Start, or the space bar, to begin timing.
  2. Press Lap to record a lap: you see each lap’s time and the running total.
  3. Press Stop (or the space bar) to pause, Start to resume, and Reset to clear the time and the laps.

What people use it for

  • Running and workouts

    Time laps on a track, intervals or how long you hold a plank.

  • Classroom and lab

    Time experiments, reading speed or a quick quiz round.

  • Speeches and practice

    Check how long a talk, a presentation run-through or a puzzle solve takes.

Questions

How accurate is this stopwatch?
The time is read from your device’s high-resolution clock instead of counting screen updates, so it doesn’t drift. The display shows hundredths of a second; your own reaction time when pressing the button is the main source of error.
Does it keep running if I switch tabs?
Yes. The elapsed time is calculated from the moment you pressed Start, so it is correct as soon as you come back, even if the screen wasn’t updating meanwhile. Closing or reloading the page resets it.
What is the difference between lap time and total time?
Lap time is the time since the previous lap (or since the start for the first lap). Total time is the time since the start, also called the split.