Start begins timing; the button becomes Stop to pause and Resume to continue.
Lap records a split without stopping the clock. The fastest lap is marked green, the slowest red.
Reset clears the time and all laps.
Press the Space bar to start/stop hands-free.
How accurate is it?
Timing uses the browser's high-resolution performance.now() clock and shows hundredths of a second. It stays accurate even if the display briefly can't repaint, because the elapsed time is always calculated from real timestamps rather than by counting frames.
Timer
How do I set a countdown?
Type hours, minutes and seconds, or tap a preset like 5 min or 25 min (handy for a Pomodoro), then press Start. You can Pause/Resume or Reset at any time. The remaining time also shows in the browser tab title.
What happens when it reaches zero?
The display turns red, the tab title shows "Time's up!", and — if the sound option is on — an alarm beeps. Press Stop alarm to silence it (it also stops on its own after a few seconds).
Why didn't the alarm play?
Browsers only allow sound after you've interacted with the page, so the alarm is generated when you press Start. If you still hear nothing, check the sound checkbox is ticked and your device isn't muted. The beep is synthesized in the browser — no audio file is downloaded.
Privacy
Does it need an account or internet?
No account, and no internet once the page has loaded — everything runs locally in your browser. Nothing is uploaded or saved; closing the tab clears it.
Will it keep running in a background tab?
The count stays correct because it is based on real timestamps, but some browsers slow down or pause timers in hidden tabs, so the alarm may fire when you return to the tab rather than exactly on time. For a critical alarm, keep the tab visible.
