Online Timer — Fullscreen Countdown
A free countdown timer with fullscreen mode and a generated alarm sound
Runs in your browser · nothing is uploaded
Time left
Ready · Set to 5min
If the screen turns off or the phone locks, the alarm may be late or silent. Keep the screen on or lengthen the auto-lock time.
Shortcuts
- Space start / pause
- R reset
- F fullscreen
Settings and a running timer are stored in this browser only. A reload picks up where it left off.
What it is
A countdown timer for anything with a fixed length: a study block, a presentation rehearsal, tea steeping, a meeting agenda item or a workout interval. Pick a preset from 1 to 60 minutes with one click, or type hours, minutes and seconds yourself up to 99:59:59. There is nothing to install, no account, and all of the work happens inside your browser.
How to use
- Click a preset or enter hours, minutes and seconds.
- Press Start. The same button turns into Pause and Resume.
- When the time is up the alarm sounds and the digits turn red. Press Stop alarm to silence it.
- Use Fullscreen for large digits on a projector or a second monitor.
- Adjust the alarm volume with the slider and press Test sound to hear it before you need it.
Keyboard shortcuts: Space to start or pause, R to reset, F for fullscreen. They are ignored while you type in a field.
How it works
- Accuracy: the timer never counts ticks. It keeps the end timestamp from
Date.now()and recomputes the difference each time the screen updates, so throttled background tabs do not drift. When the tab becomes visible again the display catches up at once. - Display: remaining time is rounded up, so 00:01 stays on screen until the time has really run out.
- Alarm: a short three-beep pattern generated with the Web Audio API, no audio files, repeated for about ten seconds.
- Notifications: optional, and the permission request only happens when you tick the checkbox.
- Storage: duration, state and volume are kept in this browser’s localStorage. Private windows may not keep them.
- Reduced motion: if your device asks for reduced motion, the progress bar does not animate.
Examples
| Use | Setting | Note |
|---|---|---|
| Deep work block | 25 min | Pair it with a 5 minute break in the Pomodoro timer |
| Soft-boiled egg | 6 min | Type 6 in the minutes field |
| Talk rehearsal | 10 min | Run it fullscreen next to your slides |
| Power nap | 20 min | Raise the alarm volume first |
| Long task | 1 h 30 min | Hours 1, minutes 30 |
FAQ
Is the timer accurate when the tab is in the background?
Yes. When you press start the timer stores the exact moment it will end, and every screen update subtracts the current time from that moment. Browsers slow down timers in hidden tabs, but that only affects how often the screen refreshes, not the result. The remaining time also appears in the tab title.
I cannot hear the alarm.
Press the test sound button first. Browsers only allow audio after you have interacted with the page, and pressing start counts. If it is still silent, check the device volume, whether the tab is muted, and the alarm volume slider on the page.
What happens if I reload the page or close the tab?
A running timer keeps its end time in your browser, so after a reload it continues counting down. If it ran out while the page was closed, it shows as finished and does not play a late alarm. Nothing is sent to a server.
How do browser notifications work?
The permission prompt only appears when you tick the notification checkbox yourself. After you allow it, one notification appears when the time is up. If you blocked it earlier, re-enable it in the site settings next to the address bar.
Will the alarm ring if my phone screen turns off?
While the timer runs, the page asks the browser to keep the screen on (Screen Wake Lock). Browsers without it, or a battery saver that refuses it, can still let the screen turn off, and a locked phone may delay or silence the alarm because browsers throttle background sound. For an alarm that matters, keep the screen on or lengthen the auto-lock time.
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