Countdown Timer
Set a duration, start the countdown, and get a signal when it reaches zero.
Countdown timer
How to use this timer
- 1
Set a duration. Type hours, minutes and seconds, or press a quick duration.
- 2
Press Start. Pause and resume whenever you like; the time left is kept.
- 3
Wait for the signal. At zero the display changes and, if enabled, a short sound plays. Reset returns to the duration you set.
Example
Set 1 hour 30 minutes and the display starts at 1:30:00. Pause at 1:12:40 and resume later: it continues from 1:12:40.
How it is calculated
The timer records when it started and how much time was left, and recalculates the remaining time from the clock on every refresh. Browsers slow down timers in background tabs, but because the remaining time comes from timestamps rather than counting ticks, it stays correct. The tab has to stay open: closing it stops the timer.
The sound is generated by your browser and only plays if the browser allows audio on the page; it can be silenced by the device’s volume or mute settings. Do not rely on this timer for anything safety-critical.
Questions
Does the timer keep running if I switch tabs?
Yes. The display may update less often in a background tab, but the time left is always correct when you return, and the page title shows the time left.