Online Stopwatch

Time anything with a precise stopwatch and lap splits.

Processed locally — nothing is uploaded

About Stopwatch & Timer

Each lap shows its own time next to the running total, with the fastest and slowest marked, because comparing one interval against another is the entire point of recording them. The clock is high-resolution rather than a once-a-second tick, so a long session does not drift.

Start a precise stopwatch and capture lap splits to compare intervals, with a countdown timer in the same view. It runs entirely in your browser.

Time anything with a lap-recording stopwatch, or count down from any duration with a clear time's-up alert — both in one tool. Use the stopwatch for workouts, cooking and speed tests, and the countdown for breaks, presentations and kitchen timers.

Record laps to compare one interval against another, or switch to the countdown for a fixed duration with an alert at the end. Both share a tab, so timing a workout and its rest period does not mean swapping tools.

Learn how this works

Frequently asked questions

How accurate is a browser stopwatch?

It uses a high-resolution timestamp clock, so it is accurate to well within a hundredth of a second — far finer than human reaction time, which is around two tenths. Your reflexes, not the timer, are the limiting factor.

What are lap times for?

A lap records a split without stopping the clock, so you can compare individual intervals across a session — per-length swim times, or how long each stage of a process takes.

Does it keep timing in a background tab?

Yes. Elapsed time is derived from timestamps rather than an interval counter, so switching tabs or minimising the window does not cause the drift you get from naive implementations.

Common Use Cases

  • Timing laps during training without a dedicated watch
  • Measuring how long a manual process actually takes
  • Timing rounds in a game or classroom activity

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