Countdown Timer
Precise online countdown timer with end alert. Set hours, minutes and seconds, watch the time tick down, and get alerted when time is up.
How to use
- Enter the target duration in the Hours / Minutes / Seconds fields, or tap one of the 1 / 5 / 10 / 25 minute quick presets.
- Click "Start" to begin. While running, the button turns into "Pause" so you can pause and resume anytime.
- During the countdown, the browser tab title shows the remaining time in real time — handy when you have many tabs open.
- When time is up, the page plays a beep and shows "Time's up!". Click "Reset" to go back and set a new duration.
- On-time alerts rely on the page running, so keep it open and in the foreground.
FAQ
Is the countdown accurate?
Yes. The timer computes the difference between a fixed end timestamp and the current time instead of counting interval ticks, so jitter in the timer never accumulates into drift. As long as the page runs, the remaining time stays exact.
What happens if I switch to another tab?
Browsers throttle timers in background tabs and may even pause them under power-saving modes, which delays the end alert. Keep this page in the foreground; when you come back, the remaining time is corrected immediately.
No sound or vibration when time is up?
Browsers only allow audio after a user interaction, so click "Start" first. If audio is still unavailable, devices that support vibration fall back to it automatically. You can also try Chrome, Edge or Firefox.
What is the maximum duration?
The hours field accepts up to 99, so the longest countdown is 99 hours 59 minutes 59 seconds — enough for cooking, studying, working or workouts.