Stopwatch — lap timing with millisecond precision
A simple in-browser stopwatch with 0.01s precision and lap (split) recording. Keeps running as long as the tab stays open, and lets you export laps as CSV. While countdown counts toward a target time, this measures elapsed time from now. There is no data input — everything stays in your browser.
How to use
Press Start to begin timing, Lap to record a split, Pause to hold, Resume to continue, Reset to clear back to 0. Once you have a few laps, Export to CSV pulls them into Excel / Google Sheets. Closing the tab ends the session (the page itself records nothing).
FAQ
- Is timing data sent to a server?
- No. Timing and CSV export both run entirely in your browser.
- How is this different from the countdown tool?
- Countdown shows time remaining until a target moment. Stopwatch measures elapsed time from now, with no preset target.
- What's the precision?
- performance.now() based, displayed to 0.01s (10ms). The browser's internal precision is finer but the display is rounded to 10ms.
- What happens if I reload the page?
- The session resets. For long-running or important measurements, keep the tab open in the background and avoid reloads.
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