SlideTimerApp
Free online countdown

Online Timer With Sound

By the SlideTimerApp team — presentation-tool makers & daily presenters. About us.
Last updated: August 2026

The short answer: this is a free online countdown timer with an alarm sound — pick a duration, press Start, and it rings when time is up while the digits turn red in the final seconds. Press Fullscreen so a whole room can see it. To keep a timer with sound on top of a PowerPoint Slide Show, download SlideTimerApp, the free desktop overlay.

How the alarm works

When the countdown hits zero, the timer plays a short alarm tone — a clear beep-beep pattern that carries across a room without being harsh — and the display flashes red. You get two cues at once: an alarm sound you can hear and a signal you can see, so it works equally well as an audible timer for a classroom and as a countdown clock on a meeting-room screen. Because web browsers only allow audio after a user action, the sound is enabled the moment you press Start; just make sure your device isn't muted. Prefer no sound at all? Mute the tab and it becomes a silent visual timer — nothing else changes.

Tip: the digits turn amber in the last minute and red in the final ten seconds, so people get a warning before the alarm — useful for wrapping up an activity or a talk smoothly.

Use it in the classroom

A timer with sound is one of the simplest classroom-management tools there is: it ends "how much longer?" and gives every activity a clear, consistent finish line. Set the minutes, press Fullscreen to fill the projector, and let students watch the countdown. See more ideas on the classroom timer page, or grab a ready 5-minute or 10-minute timer.

Use it while presenting

For talks, webinars and workshops, a visible countdown with an alarm keeps you on schedule without checking your phone. This browser timer is perfect when you're sharing a single screen — but a browser tab can't sit on top of a full-screen slideshow. For that, use the overlay app.

Why an overlay app beats a browser tab for slideshows

What you needThis web timerSlideTimerApp overlay
Alarm sound at zeroYesYes
Big fullscreen displayYesYes
Floats on top of PowerPoint Slide ShowNo (browser tab)Yes
Stays visible while you present slidesNoYes
Works in Google Slides & Canva tooTab onlyYes

Want the alarm on top of your slides?

SlideTimerApp floats a transparent countdown with a red warning and alarm over PowerPoint, Google Slides or Canva — free for Windows.

Download SlideTimerApp free ~3 MB · Windows · works offline

More timers

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Classroom timer

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Presentation timer

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Countdown for PowerPoint

Float a countdown over your Slide Show.

Frequently asked questions

Does this online timer have a sound?

Yes. This free online timer plays an alarm tone when the countdown reaches zero, and the digits turn red in the final seconds, so you get both an audible and a visual cue. Make sure your device isn't muted so the alarm can be heard.

Can I use a timer with sound in the classroom?

Yes. Set the minutes, press Fullscreen so the whole class can read the countdown on the projector, and the alarm signals when an activity is over. It's free, needs no sign-up, and collects no student data.

How do I turn the alarm sound on or off?

The alarm plays automatically at zero. To silence it, lower or mute your device or browser-tab volume. The first sound only works after you press Start, because browsers require a user action before playing audio.

How do I keep a timer with sound on top of PowerPoint?

A browser tab can't stay on top of a full-screen Slide Show. Download SlideTimerApp, a free Windows overlay that floats the countdown over PowerPoint, Google Slides or Canva and plays an alarm at zero, so the timer stays visible while you present.

Is the timer sound a beep or an alarm?

The timer plays a short, repeated alarm tone — a clear beep-beep pattern that is easy to hear across a classroom or meeting room without being harsh. Before it rings you also get a silent warning: the digits turn amber in the last minute and red in the final ten seconds.

Can I use it as a silent timer instead?

Yes. Mute your device or browser-tab volume and the countdown runs exactly the same with visual cues only — amber digits in the last minute, then red flashing digits at zero. That makes it easy to switch between a loud timer for activities and a silent one for tests or quiet work.