Online Alarm Clock

Set one or more alarms in your browser with a label, a choice of sounds, repeat days and 5- or 10-minute snooze, plus an optional desktop notification. A big live clock shows the time and how long until the next alarm.

This tool runs entirely in your browser.

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How to use the Online Alarm Clock

1Pick a time, an optional label and a sound — click “Test sound” once so the browser allows audio.
2Choose repeat days, or leave them empty for a one-time alarm, then click “Add alarm”.
3Keep the tab open; when it rings, stop it or snooze for 5 or 10 minutes.

What is the Online Alarm Clock?

The alarm runs in this browser tab: sounds are generated with the Web Audio API, so there is nothing to download, and alarms are saved in your browser (localStorage) so they’re still there after a reload. A one-time alarm switches itself off after ringing; repeating alarms ring on the chosen weekdays.

Browsers can’t ring from a closed tab, and phones and laptops may pause pages when they sleep or the screen locks. For important alarms — an early flight, medication — use your phone’s built-in alarm as well. The optional notification helps when the tab is in the background.

Frequently asked questions

Will the alarm ring if my computer goes to sleep?

No — a sleeping device pauses the browser. Keep it awake and plugged in, and leave the tab open (it can be in the background).

Why do I need to click “Test sound”?

Browsers block audio until you interact with the page. One click unlocks sound for the alarm.

Is the Online Alarm Clock free and private?

Yes. The Online Alarm Clock is free, needs no account, and runs entirely in your browser. What you type is never sent to a server or stored.

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