Free Online Countdown Timer

A countdown timer does one thing well — it tells you exactly how much time you have left.  This one arrives pre-set to 10 minutes, ready to start with one click.  Set any start time up to 99 hours, 59 minutes, and 59 seconds, press Start, and a clear alarm sounds the moment the countdown reaches zero.

Timer123's timing engine measures real elapsed time rather than relying on interval loops, so your countdown stays accurate even when your browser is busy or under load.  Pausing and resuming preserves the exact time remaining — not an approximation.  Twenty years of online timer development went into getting that right.

What to Use a Countdown Timer For

Any situation where knowing how much time remains matters more than knowing how much time has passed:

• Meetings and presentations — Set the timer to the length of your slot and start it when you begin.  A visible countdown keeps you aware of where you are without watching the clock, and the alarm signals the hard stop before you run over.
• Study and focus sessions — A countdown creates a natural sense of urgency that open-ended work sessions lack.  Knowing you have 25 or 45 minutes focuses effort in a way that "work until done" rarely does.
• Exams and timed assessments — Display the countdown full-screen on a projector so every student sees exactly how much time remains without having to ask.  Click the timer title to scroll the page header out of view for a clean full-screen display.
• Cooking and kitchen timing — Set the exact minutes and seconds your recipe calls for.  The alarm fires the moment time is up, not when you happen to check.
• Workouts and training intervals — Time a work set, rest period, or full session.  Enable Loop for automatic back-to-back intervals, or AutoRestart so a reset immediately kicks off the next round.
• Games and competitions — A countdown timer with a clear alarm is the simplest way to run a timed game, quiz bowl round, escape room, or competition segment.
• Speeches and debates — Give each speaker a hard time limit enforced by an alarm rather than a hand signal.  Set the title to the speaker's name or topic so everyone in the room knows what the countdown is for.
• Meetings running long — Set the stop time to a negative value to count through zero and into negative time.  A countdown that keeps going past zero shows exactly how many minutes over schedule the meeting has run — a useful pressure signal in any room.

Setting Your Countdown Time

The action bar under the timer display gives you direct control over the countdown:

• Start time field — Shows 00:10:00 by default.  Click it and enter any time value up to 99:59:59.  This is the time the countdown begins from, and where Reset returns to.
• Stop time field — Shows 00:00:00 by default — the point at which the alarm sounds.  Set it to a negative value like -00:05:00 to count through zero into overtime.
• Swap button — The arrow between the start and stop time fields instantly swaps the two values.  One click turns your countdown into a count-up timer without retyping anything.
• Set button — After changing start or stop time values, click Set to apply them and reset the timer to the new start time.
• Alarm button — Click to preview your current alarm sound at the current volume setting.  Useful for confirming the alarm will be heard in your environment before you start timing.
• Loop — When enabled, the timer automatically resets and starts again the moment it reaches the stop time.  Useful for repeating intervals that run continuously until you stop them.
• Save and share — Click the share icon to copy a URL with all your current settings embedded.  Anyone who opens that link loads your exact countdown configuration — start time, stop time, alarm, display, title — ready to start with one click.

Countdown Timer — Common Questions

Does this timer work on phones and tablets?

Yes.  The countdown timer works on any modern browser across desktop, mobile, and tablet.  The display scales automatically to fit your screen size.

Will the alarm sound if I switch to another tab?

For reliable audio, keep the timer visible in an active browser tab with the window not minimized.  Browsers may throttle or mute background tabs, which can affect alarm playback.  If the alarm matters, keep the tab in view.

Can I set the countdown to any time, not just 10 minutes?

Yes.  Click the start time field in the action bar, enter any value from one second up to 99:59:59, then click Set.  The timer resets to your new start time and is ready to count down from there.

Can I make it count past zero into negative time?

Yes.  Set the stop time to a negative value — for example -00:05:00 — and the timer counts through zero and continues into negative time.  The alarm sounds at the stop time you set.  Useful for meetings, lectures, or any situation where seeing how far over time is as important as the countdown itself.

Does pausing the timer lose any time?

No.  Pausing preserves the exact time remaining.  When you press Start again the countdown resumes from precisely where it stopped — not an approximation.

How do I share this countdown with my class or team?

Configure the timer — start time, stop time, alarm, title, display settings — then click the icon under the time display and copy the URL shown.  Anyone who opens that link loads your exact countdown setup, ready to start with one click.

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