Online countdown timer
A free timer that runs in the browser. Pick a duration, turn on the alarm and open fullscreen for class, cooking or a talk.
Alarm sound
Volume
Quick presets
More tools
How to use it
- Open Options, then set the hours, minutes, seconds and alarm sound.
- Press Start. Space pauses. R returns the timer to 5 minutes.
- Press Copy link to share this exact timer. Keep the tab open so the alarm can ring.
Common questions
Which page counts to a calendar date?
The date countdown page. This page counts a length of time in hours, minutes and seconds.
Does the tab have to stay open?
Yes. The computer also has to stay awake. The alarm uses the browser, so a closed tab cannot ring.
What if the alarm stays silent?
Click the page once so the browser allows sound, then check the device volume and the mute button. S mutes.
How do I share this timer?
Press Copy link. The address carries the duration, sound, volume, repeat and theme.
What do the arrow keys do while it runs?
Up adds 10 seconds and down subtracts 10 seconds, even while the timer is running.
While it runs
Pause and resume with one click or the Space key.
R returns the timer to 5 minutes.
Up and down arrows add or subtract 10 seconds, even while running.
Fullscreen or the F key is useful when you present to a class.
Keep this tab open. Sleep mode can cut off the alarm.
If you have not clicked yet, some browsers block sound.
For several alarms at clock times, open Alarm. For focus and breaks, open Focus.
About
donghodemnguoc.org is a free set of time tools: countdown, alarm, stopwatch, clock and a few date calculations.
Everything runs in the browser, with nothing to install. Support and feedback: support@donghodemnguoc.org.
A shared link keeps the duration and the settings. The tab must stay open for the alarm.