Stopwatch — High-Precision with Laps
A simple, accurate online stopwatch with millisecond precision and lap recording. Use it for workouts, kitchen timers, presentations, or any timing task.
How to use the online stopwatch
- Press Start. Click Start (or hit the spacebar) to begin timing. The display updates every millisecond.
- Record laps. Click Lap (or hit L) to record a split time without stopping the clock. All laps appear in the table below.
- Pause and resume. Click Pause to stop the clock without resetting. Click Start to resume from where you paused.
- Reset and export. Click Reset to zero the clock. Click Export to download all lap times as CSV.
Frequently Asked Questions
- How accurate is it?
- Millisecond precision (1 ms) using performance.now(). Browser timer resolution may round to 5ms in some privacy modes.
- Does it run if I switch tabs?
- Yes. The stopwatch continues in the background and stays accurate when you return to the tab.
- Does it work offline?
- Yes. After first load, the page works fully offline.
- Can I record split times?
- Yes. Use Lap (or L key) to record splits. Displayed as both lap time (since last lap) and total time.
- Does it work on mobile?
- Yes. Touch-friendly buttons on iOS Safari and Android Chrome.
- Are my times stored?
- Laps stay in browser memory only. Refresh clears them. Export to CSV if you need to keep results.
Use Cases
- Time workouts and interval training
- Time kitchen / cooking tasks
- Time a speech or presentation rehearsal
- Record split times for running or cycling
- Quick timing during scientific or coding experiments