Live alarm
Online Alarm Clock
Set an alarm for a specific time of day, with a fullscreen ringing display, snooze and a small set of alert sounds.
Loading your local time…
How this calculator works
Enter the time you want to be alerted at and press Arm. The alarm shows exactly when it will ring — today or tomorrow, whichever comes next — and counts down to that moment.
Pause suspends monitoring; Resume continues counting down to the same set time. If that time passed while paused, the alarm rings when you resume. Disarm cancels it and unlocks the time field for a new one. Once it rings, Snooze delays it by 9 minutes, and Dismiss turns it off.
Pick one of a small set of alert sounds and preview it at your chosen volume before arming — sound only ever plays after you've interacted with the page at least once, since browsers block audio otherwise.
Fullscreen mode enlarges the display for a room: a desk, a nightstand, a shared screen. It uses your browser's fullscreen feature where available; if that isn't supported, the large-display view still works without going edge-to-edge.
This page has to stay open on an awake device to ring. It is not a dependable alarm across a full device sleep, a closed browser, a terminated tab, or OS/browser throttling — nothing is saved, so closing or reloading the page cancels it.
The tool is arithmetic only. Where legal, payroll, holiday, timezone or jurisdiction-specific rules matter, the page states what is and is not included.
Frequently asked questions
Will this ring if I close the tab or my laptop sleeps?
No. This alarm only works while the page stays open on a device that's awake. Closing the tab, closing your laptop lid, letting your device fully sleep, or your browser being throttled in the background can all stop it from ringing. If you need a guaranteed wake-up, use your phone or a physical alarm clock as a backup.
Does the sound play automatically?
No. Browsers block audio until you've interacted with the page, so sound only ever plays after you've pressed Arm or Preview sound at least once in the current visit.
What happens if the time I set doesn't exist, or happens twice, because of a clock change?
It's disclosed, never guessed. If your chosen time falls in a daylight-saving spring-forward gap, the alarm is set for the next day that time actually occurs. If it falls during a fall-back, so the same clock time happens twice, the alarm is set for one specific occurrence and the page states which one and why.
What does Snooze do?
It stops the current ring and re-arms the alarm for 9 minutes later.
Can I set this to repeat every day?
Not in this version — each alarm is a one-time arm, not a recurring schedule. Set it again for the next time you need it.
How is this different from the Countdown Timer?
Countdown Timer counts down a duration you enter, like 25 minutes. This tool rings at a specific clock time you choose, like 7:00 AM, whether that's a few minutes away or most of a day away.
Is my alarm saved if I close the page?
No. Nothing is stored anywhere — closing or reloading the page cancels it.