Does it keep timing if I switch tabs?

Yes. The stopwatch is built on absolute epoch time (Date.now()), so switching tabs or returning after a browser pause does not add tick-count drift. The elapsed time is recalculated from the real clock when the page updates.

How do I record a lap?

Click the Lap button while the stopwatch is running, or press the L key. Each lap entry shows the split (time since the last lap) and the running total. The most recent lap is highlighted at the top of the list.

Can I save my lap times?

Yes. Click "Export CSV" after recording at least one lap. Your browser downloads a stopwatch-laps.csv file containing each lap number, split time, and total time.

Online Stopwatch — laps, CSV export, fullscreen

About this stopwatch

This is a clean, fast stopwatch for timing anything from a sprint to a presentation. Hit Start to begin, Lap to mark splits, and Stop to pause. The elapsed time is computed from the real system clock — not accumulated tick counts — so it catches up cleanly when the page updates after tab switches or browser pauses. Use fullscreen for a big classroom display, and export your laps to a CSV for further analysis in a spreadsheet.

Common uses

Athletics and fitness — track intervals, splits and personal bests.
Cooking — time multiple stages without resetting between them.
Presentations and debates — keep speakers to their allotted time.
Development and testing — measure how long a build or process takes.
Games — any activity that needs a running clock with recorded splits.

Questions

Does it keep timing if I switch tabs?: Yes. The stopwatch is built on absolute epoch time (Date.now()), so switching tabs or returning after a browser pause does not add tick-count drift. The elapsed time is recalculated from the real clock when the page updates.
How do I record a lap?: Click the Lap button while the stopwatch is running, or press the L key. Each lap entry shows the split (time since the last lap) and the running total. The most recent lap is highlighted at the top of the list.
Can I save my lap times?: Yes. Click "Export CSV" after recording at least one lap. Your browser downloads a stopwatch-laps.csv file containing each lap number, split time, and total time.