Countdown Timer
Set a duration and let it run down, with an alarm at zero. Entirely in your browser.
Runs entirely in your browser. Nothing is uploaded, logged or stored.
00:00
A bare number means minutes. 90s, 1h30m, 1:30 and 1:30:00 all work too.
Type how long you want, press start, and watch it run down. The alarm sounds at zero and the page title counts with you, so it is still readable from a tab you are not looking at.
How it works
A bare number is read as minutes, which is what a timer is nearly always asked for. Where that would be ambiguous, say which unit you mean: 90s, 45min, 2h. Units can be combined and repeated, so 1h30m and 1h 30m 15s are both fine.
The clock forms work as you would write them by hand: 1:30 is a minute and a half, 1:30:00 is an hour and a half.
When it reaches zero the alarm is synthesised in the page rather than downloaded, so it works offline and there is nothing to wait for. Browsers only allow sound after a click, which the start button provides.
Examples
| Case | Input | Result |
|---|---|---|
| A bare number is minutes | 5 | 05:00 |
| Seconds, said explicitly | 90s | 01:30 |
| Hours and minutes together | 1h30m | 1:30:00 |
| The clock form | 1:30 | 01:30 |
Frequently asked questions
Does it keep running if I switch tabs?
Yes, and it stays accurate. Browsers slow a background tab down to save power, so a timer that counted its own ticks would fall behind. This one reads the clock and works out how much time has actually passed, so coming back to the tab shows the right number rather than a caught-up one.
Will the alarm sound if the tab is in the background?
Usually, but not always: some browsers and most phones suspend audio in a tab that has been in the background for a while, and a locked phone almost certainly will. The countdown itself is unaffected — only the sound is at the browser's discretion.
Does 5 mean five minutes or five seconds?
Minutes. Every timer on the web decides this silently and they do not all decide the same way, so this one says which it picked. Write 5s when you mean seconds.
Can I share a link to a timer?
You can share the duration: the link fills the field in and waits for whoever opens it to press start. It cannot share a timer in progress, because a link would have no way of knowing when the person opened it.
Good to know
- The clock is read from your device, not counted. A timer that added up its own ticks drifts, and browsers slow those ticks right down in a tab you are not looking at — so a five minute timer left in the background would come back minutes late. Every display here is computed from the time it started, which makes switching tabs and locking the screen harmless.
- Nothing is stored and nothing is sent. Close the page and the timer is gone, which is also why a share link carries the settings and never a timer in progress.