Free Countdown Timer
Set a countdown or an alarm for a clock time. Use presets, pause and reset, hear a built-in alarm, and see time left in the tab title.
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How to set a countdown timer or a clock-time alarm
Choose a duration in hours, minutes and seconds, pick a preset or set an alarm for a time of day. The page beeps and can notify you when time is up.
- Choose Countdown timer or Alarm at clock time.
- Enter hours, minutes and seconds, tap a preset, or pick the alarm time. Add an optional label.
- Keep the alarm sound on, set the volume and press Test sound if you want to check it. Turn on browser notifications if you like.
- Press Start. Pause and Resume as needed; the remaining time also shows in the browser tab title.
- When the alarm rings, press Stop alarm.
When a browser countdown timer helps
A countdown timer is useful whenever something needs to happen after a set amount of time. Cooks use it for pasta and baking, students and remote workers use 25 minute focus sessions with short breaks, and presenters use it to keep talks on schedule. Teachers often project a timer during tests or group activities so everyone can see the time left.
The alarm at clock time mode covers the other common need: being reminded at a particular time rather than after a duration. Set it for the start of a meeting, the end of a parking session or when to leave for school pickup.
Because the remaining time appears in the browser tab title, you can keep working in other tabs and still glance at the countdown.
Worked example: pausing a focus session and setting an alarm
Suppose you start a 25 minute preset at 2:10:00 PM. The timer shows it will ring at 2:35:00 PM. At 2:22:30 PM you pause with 12:30 remaining. You resume three minutes later at 2:25:30 PM, so the new ring time is 2:25:30 plus 12 minutes 30 seconds, which is 2:38:00 PM.
For the clock time mode, imagine it is 11:40 PM and you set the alarm for 06:30. That time has already passed today, so the tool sets it for tomorrow and the display starts at 6:50:00, the 6 hours and 50 minutes until 6:30 AM.
How the timer stays accurate
When you press Start, the tool records the exact moment the timer should finish. Every display update calculates the remaining time as that end moment minus the current clock time, so the countdown cannot drift even if the browser updates the screen less often in a background tab. The display rounds partial seconds up, so it reads 00:01 until the final second has truly passed.
The alarm beeps are scheduled on the Web Audio clock at the moment you press Start, which keeps them on time even when page timers are delayed. If the audio clock and the system clock drift apart, for example after the device wakes from sleep, the tool reschedules the sound. Pausing cancels the scheduled beeps and resuming schedules them again.
Notifications are optional and use your browser's permission prompt. Some mobile browsers do not show notifications from web pages at all.
Common countdown timer mistakes
The most common problem is closing the tab or letting a phone lock for a long time. Browsers can suspend pages that are not visible on mobile devices, which stops both the countdown and the sound. For long or critical alarms, keep the screen on or use your phone's built in clock app as a backup.
Another mistake is leaving the device muted or the volume low. Press Test sound before relying on the alarm. Finally, remember that the clock time mode uses your device's time zone and clock, so an incorrect system clock means an incorrect alarm.
Useful tips and limitations
- Keep the tab open and your device volume up, because closing the tab or letting a phone suspend the browser can stop the alarm.
- Use the label field to name timers such as Tea or Oven so the tab title and notification tell you which one finished.
- Press Test sound before an important timer to confirm your speakers or headphones are working.
- For a focus routine, alternate a 25 minute preset with a 5 minute preset.
Common questions
Does the Countdown Timer work in a background tab?
Yes, while the page stays open. Time left is calculated from the clock and the alarm sound is scheduled in advance with Web Audio, so throttled background timers do not delay it.
Do I need to download a sound file for the Countdown Timer alarm?
No. The beeps are generated in your browser with the Web Audio API, so no audio file is needed.
How does the Countdown Timer alarm at clock time mode choose the day?
It uses your device's clock. If the time you pick has already passed today, the alarm is set for the same time tomorrow.
What is the longest duration the Countdown Timer accepts?
Up to 99 hours, 59 minutes and 59 seconds. Hours accept 0 to 99, and minutes and seconds accept 0 to 59.
How long does the Countdown Timer alarm keep beeping?
It plays a repeating three-beep pattern for 30 seconds. The screen keeps showing that time is up until you press Stop alarm.
Why did I not get a Countdown Timer notification on my phone?
Some mobile browsers do not allow notifications from regular web pages, and notifications only appear after you grant permission. The on-page message and alarm sound still work while the page is open.
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