A countdown timer with an alarm
A countdown timer helps you stay on track: give yourself 25 minutes to finish a task, time a 10-minute break, cook rice for exactly 12 minutes, run a quiz round, keep a meeting to time or let children know how long until screen time ends. You can also count down to a date, such as an exam, a festival, a product launch or a holiday. When the timer reaches zero, an alarm sounds and the browser tab title changes so you notice even if you are working in another tab.
How to use the timer
- Enter hours, minutes and seconds, or click a preset.
- Or pick a date and time to count down to.
- Click Start. Use Pause and Resume as needed, and Reset to start again.
- Keep "Play alarm sound" ticked and your device volume on to hear the alarm.
Why the timer stays accurate
Browsers slow down scripts in background tabs to save battery. A simple timer that counts "one second at a time" would then run late. This timer stores the exact finishing moment and calculates the remaining time from the clock each time it updates, so it stays accurate even if the tab is in the background for a while.
Popular ways to use a countdown
- Focused work: 25 minutes of work followed by a 5-minute break is the Pomodoro method. For automatic cycles, use our Pomodoro Timer.
- Exams and practice tests: simulate real exam conditions.
- Classrooms: show a large timer on the projector for activities.
- Exercise: time a plank, a stretch or rest between sets.
- Cooking: boil eggs (about 9–10 minutes for hard-boiled) or brew tea.
Frequently asked questions
Why did I not hear the alarm?
Some phones block sound until you tap the page, and silent mode can mute browser audio. Start the timer by tapping the button, and keep the volume up.
Will the timer continue if I close the tab?
No. Keep the tab open until it finishes. It can be in the background.
How do I time something counting up?
Use the Online Stopwatch.