BrowserTools

Countdown Timer

Set any countdown with alarm sound

By Guga — BrowserTools maintainer, Tbilisi, Georgia Updated 2026-09-21
Free Private No uploads
What is Countdown Timer?

Type an hour, minute and second figure, or hit one of the eight presets from one minute up to an hour, and the countdown starts on a wall-clock deadline rather than by counting ticks. That distinction matters: the deadline is a timestamp, so the remaining time is recalculated from the current time on every frame, and a frame that gets dropped or throttled does not make the timer lose time. Pause and resume work off the same stored deadline, so resuming picks up the exact value left. A progress bar tracks the fraction remaining. At zero a four-beep alarm sounds, generated with the Web Audio API at 880 Hz, and the panel switches to a 'Time is up!' state until you reset it. Browsers require a click before audio is permitted, which pressing Start satisfies.

Set a countdown for minutes or hours, with presets for common durations, a full-screen mode and an audible alarm at zero. Perfect for workouts, cooking and timeboxing.

Private Countdown Timer In Your Browser

Countdown Timer is processed locally with client-side JavaScript. Your files never touch a server, and there is no queue to wait in.

Step-by-Step

How to use Countdown Timer

1

Enter an hour, minute and second figure, or click a preset button such as 5 min or 45 min.

2

Press Start — the duration panel hides and the progress bar begins to drain.

3

Press Pause to hold the remaining time, then Start again to resume from the same point.

4

Wait for the beep at zero, or press Reset to clear it back to the set duration.

Key Capabilities
  • The countdown holds a wall-clock deadline and derives remaining time from the current time each frame, so throttled frames do not accumulate error.
  • Pause stores the exact remaining value and resume recomputes the deadline from it, so no time is lost or gained across a pause.
  • Eight presets cover one, three, five, ten, fifteen, twenty-five and forty-five minutes plus an hour.
  • The alarm is synthesised with the Web Audio API as four short 880 Hz beeps, requiring no audio file to load.
Common Use Cases
  • A cook timing a pasta or rest phase sets three minutes and steps away from the stove.
  • A language learner using a timed speaking exercise gets an audible signal rather than watching digits.
  • A meeting chair keeps a discussion phase to fifteen minutes with the timer visible on a shared screen.
Clear Answers

Frequently Asked Questions

Why do I need to interact before hearing the alarm?
Every browser blocks audio until the page has had a user gesture. Pressing Start is that gesture, which is why the alarm reliably fires afterwards.
What happens if I switch tabs while it runs?
The deadline is a timestamp, so the countdown is still correct when you come back. The alarm may sound late rather than at the exact moment, because background tabs have their timers throttled — treat it as a wake-up cue, not a precision trigger.
Can it run past an hour?
Yes. The hour field accepts values up to 99, so anything under a hundred hours will run, with hours appearing in the display once the countdown passes sixty minutes.
Why does the display show centiseconds on a countdown?
It shows a decimal tail for visual consistency with the display style. The meaningful precision is the second; the fraction is there so the digits do not jump around.