About this tool
A stopwatch measures elapsed time from a manual start, with the option to record lap times. The timer mode counts down from a set duration with a circular progress visualisation. Both run in your browser with precision driven by the browser's animation frame loop, accurate to the centisecond.
When the timer is running, the page title updates with the remaining time — useful as a glanceable indicator while you work in another tab.
How to use it
- 1Choose between Stopwatch and Timer at the top.
- 2For the stopwatch: press start, hit Lap to record splits, press stop to pause, reset to clear.
- 3For the timer: enter hours, minutes, and seconds, then start. Watch the circular progress ring deplete.
- 4Best and worst laps are highlighted in green and red.
Common use cases
- Timing workouts, intervals, or exercise sets
- Cooking — boiling, baking, marinating
- Speed runs, gaming, or productivity sprints (Pomodoro)
- Conducting timed tests, interviews, or presentations
- Lap timing for running, cycling, or swimming sessions
Frequently asked questions
How precise is the timing?
The stopwatch uses requestAnimationFrame, which updates at the browser's refresh rate (typically 60 Hz). Display precision is to the centisecond (1/100s).
Will it keep running if I switch tabs?
Yes. The internal clock continues regardless of tab focus. The display catches up when you return.
Does the timer alarm when finished?
The timer pulses visually and the page title indicates completion. Browsers no longer allow auto-playing audio without user interaction, so there is no automatic sound.
Can I record more than 10 laps?
There is no hard cap. The list scrolls. Best and worst times are highlighted as you go.