Countdown Timer
A free online countdown timer with an alarm. Set hours, minutes and seconds, press start and keep working — it runs entirely in your browser and beeps when time is up.
How to use the countdown timer
- Set the time. Type hours, minutes and seconds into the boxes, or hit a quick-start button such as 5 min, 25 min or 1 hour to launch instantly.
- Start the countdown. Press Start and watch the big display and progress bar tick down. The remaining time also appears in the browser tab title, so you can switch to other tabs and still keep an eye on it.
- Pause, add time or wait for the alarm. Use Pause and Resume at any point, press +1 min to extend a running timer, and when the countdown reaches zero the display flashes and an alarm beeps until you stop it.
About this tool
This free online countdown timer is handy for anything with a deadline: Pomodoro work sprints, cooking and baking, boiling eggs, workout intervals and rest periods, exam practice, presentations, board-game turns, or getting kids out the door on time. The timer is driven by your device’s clock rather than a simple ticking counter, so it stays accurate to the second even if the tab is left in the background for a long time — when the tab is throttled by the browser, the timer catches up instantly and still finishes at the right moment.
There is nothing to install and no account to create. The page runs entirely in your browser: no data about your timers is sent to any server, and once the page has loaded it keeps working without an internet connection. The alarm is generated locally with the Web Audio API, so it works offline too. You can set anything from one second up to 100 hours, and values over 59 are accepted — entering 90 minutes simply counts down from 1:30:00.
Frequently asked questions
Will the timer keep running if I switch tabs or minimize the browser?
Yes. The countdown is calculated from your system clock (an end timestamp), not from counting ticks, so background-tab throttling cannot make it drift. The remaining time is shown in the tab title, and the alarm sounds when the countdown ends. Only closing the tab or the browser stops the timer.
Why don’t I hear the alarm sound?
First check that Play alarm sound is ticked and use the Test sound button to confirm audio works. Then make sure your device volume is up and the tab is not muted (right-click the tab and choose unmute). Browsers only allow sound after you interact with the page, which is why the alarm is enabled the moment you press Start.
What is the longest countdown I can set?
Up to 100 hours in total. You can combine the fields freely — 2 hours 90 minutes, or 600 seconds, are both valid and get normalized automatically. The minimum is 1 second.
Can I add time or pause without losing my place?
Yes. Pause freezes the remaining time exactly, and Resume continues from that point. +1 min adds 60 seconds to a running or paused countdown, which is perfect when a task needs just a little longer.