Free Online Countdown Timer

Set a custom countdown in hours, minutes, and seconds — alerts you when time is up.

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How to Use the Countdown Timer

1

Set your time

Enter hours, minutes and seconds, or click a quick-set button (1 min, 5 min, 25 min, etc.).

2

Start the countdown

Click Start. The timer counts down and the browser tab shows the remaining time so you can keep an eye on it.

3

Get alerted

When the countdown reaches zero, the display flashes and an alert notifies you — even if the tab is in the background.

Frequently Asked Questions

What is the maximum countdown time?

Up to 99 hours, 59 minutes, and 59 seconds — plenty for any task, presentation, or event countdown.

Will it alert me when the tab is inactive?

Yes. The timer runs in the background. A browser alert will appear even when you are on another tab.

Can I pause and resume the timer?

Yes. Click Stop to pause and Start again to resume from where it left off.

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What this countdown timer does

A countdown timer counts down from a duration you set — minutes and seconds — and alerts you the moment time runs out. Set it, press Start, and get on with what you're doing; the timer keeps counting accurately in the background because it tracks real clock time, not just screen updates. Pause and resume whenever you need, or reset to go again.

It's the opposite of a stopwatch, which counts up to measure how long something takes. Use a countdown when the duration is decided in advance: "boil for 7 minutes", "give the presentation 20 minutes", "revise for 45 minutes then break".

Good ways to use a countdown timer

Tips for effective time-boxing

The magic of a countdown is commitment: decide the duration before you start, make the remaining time visible, and treat the alarm as a hard stop. Research on time-boxing consistently shows people estimate better and drift less when the clock is external — willpower is spent deciding once, not every minute.

Frequently asked questions

Will it still go off if I switch tabs?

Yes — the timer tracks real elapsed time, so backgrounding the tab doesn't slow it down. Keep the tab open so the alert can fire.

Can I pause and resume?

Yes. Pause freezes the remaining time; Start continues from exactly where you left off.

Is anything uploaded?

No — everything runs locally in your browser. No account, no data sent anywhere.

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