Online Stopwatch

Start, stop and resume the stopwatch with centisecond precision, measured with the browser’s high-resolution clock. Record laps to see each lap time and the running split, with the fastest and slowest laps highlighted. Use Space, L and R as shortcuts, and copy or download your laps as a CSV file.

How to use the Online Stopwatch

1. Press Start (or Space) to begin timing.
2. Press Lap (or L) to record a lap while running.
3. Press Stop to pause and Resume to continue.
4. Copy the laps or download them as CSV; press Reset (or R) to start over.

Features

• Centisecond display using performance.now()
• Lap and cumulative split times
• Fastest and slowest lap highlighting
• Keyboard shortcuts: Space, L, R
• Copy laps or download as CSV

Benefits

• Time workouts, laps, presentations or experiments
• Analyse lap consistency at a glance
• Works offline once the page has loaded

Frequently asked questions

How accurate is the stopwatch?

It uses the browser’s high-resolution monotonic clock, so elapsed time is not affected by system clock changes. The display shows hundredths of a second.

What is the difference between lap and split time?

Lap time is the time for that lap alone. Split time is the total elapsed time when the lap was recorded.

Do the shortcuts work while I type?

No. Shortcuts are ignored while a text field has focus so they don’t interfere with typing.

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