Online Stopwatch
Free fullscreen stopwatch — laps, keyboard shortcuts, 1/100 s accuracy.
How to use the stopwatch
Press Start or the space bar to begin. Press Lap (or L) to record split times without stopping the clock. Press R to reset. Press F for fullscreen — ideal for classrooms, workouts and presentations.
| Action | Key |
|---|---|
| Start / Pause / Resume | Space |
| Record a lap | L |
| Reset | R |
| Fullscreen | F |
Why this stopwatch is drift-free
Many web stopwatches count animation frames, and browsers pause or slow those in background tabs — so a “2-minute” stopwatch can end up showing 1:40. StopwatchHQ instead derives elapsed time from your device's system clock timestamps. Switch tabs, minimize, cover your phone screen: the displayed time stays exact to the hundredth of a second.
Use cases
- Classrooms — fullscreen timing for quizzes, debates and exams visible from the back row.
- Workouts — time sets and rest periods, then review your lap list to see rep pace.
- Lab & cooking — record split times for multi-step processes without touching the mouse.
- Presentations — keep speakers on schedule with a big, readable clock.
Related tools
Need an alert when time is up instead? Try the online countdown timer. Working in focused sprints? The pomodoro timer runs the classic 25/5 cycle. Training in intervals? The interval timer handles work/rest automatically.