Live countdown
Countdown Timer
Set a duration and count down to zero, with a fullscreen display for events, speakers and classrooms.
05:00
Set a duration and press Start.
Keyboard shortcuts
- Space — Start, pause or resume
- R — Restart from the full duration
- F — Enter or exit fullscreen
- M — Mute or unmute the alert
How this calculator works
Enter hours, minutes and seconds — or pick a preset — then press Start to count down to zero. Pause freezes the remaining time exactly where it stood, and Resume continues from there.
The duration fields lock once you start, since changing them mid-countdown would make the remaining time jump. Restart immediately starts a fresh countdown from the same duration; Reset stops and unlocks the fields so you can set a different one.
When the countdown reaches zero, the display clearly reads "Time's up" and, unless muted, plays a short audible alert. The alert only ever plays after you've pressed Start at least once — nothing plays automatically on page load, and the Mute toggle is visible before you start.
Fullscreen mode enlarges the display for a room: speakers, meetings, classrooms and workshops. It uses your browser's fullscreen feature where available; if that isn't supported, the large-display view still works without going edge-to-edge.
This page has to stay open to keep timing. Nothing is saved — closing or reloading the tab resets it, and it is not a dependable background alarm across a full device sleep.
The tool is arithmetic only. Where legal, payroll, holiday, timezone or jurisdiction-specific rules matter, the page states what is and is not included.
Frequently asked questions
Does the alert sound automatically when the page loads?
No. Browsers block audio until you've interacted with the page, and this tool only ever plays its alert after you've pressed Start at least once in the current visit. You can also mute it beforehand with the visible Mute toggle.
Can I change the duration while it's counting down?
Not directly — the hours/minutes/seconds fields lock once you start, so the remaining time stays consistent. Use Reset to stop and unlock the fields for a new duration, or Restart to run the same duration again from the top.
What's the difference between Restart and Reset?
Restart immediately begins a fresh countdown from the same duration and keeps running — the fast option for going again. Reset stops and returns to the setup screen with the duration fields editable again.
Does it stop or repeat at zero?
It stops. The display holds at "Time's up" until you press Restart or Reset — it does not loop or count into negative time.
Does switching tabs or minimizing the browser affect the countdown?
No. Remaining time is calculated from your device's clock, not a repeating timer, so it stays correct even after the tab was inactive or backgrounded — the display just catches up once it's visible again.
What if my device fully goes to sleep, like closing a laptop lid?
That's different from switching tabs and isn't guaranteed. A full system sleep can pause the browser entirely, and how much of that time (if any) is reflected when it wakes depends on your operating system and browser, not this page. If accurate timing across a real sleep matters, keep the device awake — fullscreen mode's wake lock helps where it's supported, but check the on-page note, since it isn't available everywhere and is a convenience, not a guarantee.
Can I use this as a stopwatch instead?
Not directly — this tool counts down to zero from a set duration. Use the Stopwatch for open-ended count-up timing with laps.
Is the countdown saved if I close the page?
No. Nothing is stored anywhere — closing or reloading the page resets it.
Can I set this to go off at a specific time, like 7 AM?
Not directly — this tool counts down a duration you enter (like 25 minutes), not a specific clock time. Use the Online Alarm Clock to set an alarm for a specific time of day instead.