Will the alarm fire if my tab is in the background?

JavaScript timers may be throttled in background tabs, but the alarm fires based on the wall-clock time, so it will still trigger when the tab regains focus. For best results keep this tab visible.

Why doesn't the beep play?

Browsers require a user gesture before audio can play. Click “Arm alarm” (a gesture) before the alarm time — then the Web Audio API is unlocked and the beep will sound.

How does snooze work?

Snooze reschedules the alarm 5 minutes into the future and stops the current beep. Each snooze is tracked in a counter so you can see how many times you've hit it.

Can I set multiple alarms?

This tool runs one alarm at a time. Open the tool in another browser tab to run a second alarm in parallel.

Is the alarm sound reliable for waking me up?

It's a browser-based alarm, not a system alarm. For critical wake-ups, set a backup alarm on your phone. Keep your device volume up and the tab visible.

Does it work offline?

Yes. Once the page is loaded, no network is needed. Install the site as a PWA and the alarm will work even without an internet connection.

Alarm Clock

Set an alarm that beeps, flashes and toasts — snooze included.

100% private — no uploads Date & Time ToolsFree & unlimited Read tutorial

See how it works

Watch a quick simulation of this tool in action — no file needed.

How to use Alarm Clock

Follow these steps — everything happens instantly in your browser.

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Step 1. Set the alarm time in 24-hour format using the time picker.
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Step 2. Click “Arm alarm” — the badge shows how many minutes remain.
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Step 3. When the alarm fires, a beep loops, the screen flashes and a toast appears.
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Step 4. Click “Snooze 5 min” for a short delay, or “Dismiss” to stop and disarm.