Free Online Stopwatch Tool

1. Press Start to begin timing.
2. Press Lap to mark a segment — the lap and total times are recorded below.
3. Press Stop to pause, or press the button again to Resume from where you left off.
4. Press Reset to clear elapsed time and the lap list.

Stopwatches are useful well beyond athletics: cooking, presentation rehearsals, study sprints, timing how long a process takes, or time-boxing meetings. This one displays elapsed time as HH:MM:SS.mmm using performance.now(), so the milliseconds are accurate rather than decorative.

The Lap button captures both the time since the last lap (the segment) and the running total at that moment. Both are listed below the main display, newest first, so you can compare segments at a glance — useful for interval workouts, debate-round timing or chess analysis. Stop pauses the clock without clearing; pressing Start again resumes from where you left off. Reset clears elapsed time and the lap list together.

Closing or refreshing the tab discards the running state, so note your lap times before navigating away. The stopwatch consumes negligible CPU when running and works without an internet connection.