Alarm Clock
Set an alarm for a time of day, not a countdown. Keep this tab open.
Current time
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Your alarms
No alarms set. Add one above and keep this tab open.
Alarm
How it works
An alarm is stored as the next instant it should fire, recalculated whenever it repeats. Keeping a target instant rather than a countdown is what lets an alarm survive a background tab or a machine that goes to sleep — on waking, the page compares now against the target instead of trying to reconstruct lost ticks.
Alarms live in this browser's local storage, so they are still there when you come back, and they are never sent anywhere. The obvious limitation is that a browser alarm only fires while the page is open. It is not a replacement for your phone's alarm clock, which the operating system can wake for.
Sound is generated locally rather than fetched, so it works offline. Browsers require an interaction before allowing audio, which setting an alarm provides. Granting notification permission lets an alarm reach you when the tab is not in front.
Examples
A reminder during focused work. Set an alarm for the end of a block and leave the tab open behind your editor. The notification arrives even though the page has not been in front for an hour.
A recurring stand-up. Set a repeating alarm for the same time each weekday; the next instant is recomputed after each firing rather than accumulating drift.
A reminder to leave. Where the consequence of missing it is real, set your phone as well. A browser alarm cannot fire if the browser is closed, and being explicit about that is more useful than pretending otherwise.
Practical notes
The important limitation is worth stating plainly: an alarm here only fires while this page is open in a running browser. Close the tab, quit the browser or shut the machine down and nothing happens. For anything you must not miss, use your phone.
Notifications are what make an alarm useful in practice, because they reach you when the tab is behind other windows. Permission is requested only when you ask for it, and the alarm still sounds without it as long as the page is open and audio has been unlocked.
Alarms are stored in this browser and nowhere else. They survive a reload and a restart, they are never uploaded, and they do not appear on your other devices. Clearing site data removes them.
Frequently asked questions
Will it ring if I close the tab?
No. This is a page in your browser, not an installed app, so the tab has to stay open. If your device sleeps, the alarm is reported as missed when the page wakes up.
Will it ring if the tab is in the background?
Usually yes, though browsers throttle background tabs so it can be a little late. Enabling notifications makes the alert visible when the tab is hidden.
Are my alarms saved?
Yes, in this browser only. They are restored when you come back to the page.
Will an alarm fire if I close the browser?
No. A page alarm only works while the page is open. For anything that genuinely matters, use a device alarm the operating system can wake for.
Why was there no sound?
Browsers block audio until the page has been interacted with. Setting or editing an alarm satisfies that; an alarm restored on load may stay silent until you click something.
Can I set a repeating alarm?
Yes. The next firing instant is recalculated after each one, so a daily alarm does not accumulate drift.
Will it wake a sleeping computer?
No. A web page cannot wake a suspended machine — only the operating system can, which is why a device alarm is the right tool for anything critical.
Can I change the sound?
The tone is generated locally rather than loaded from a file, so the choices are the ones offered rather than an arbitrary upload.
Can I snooze?
Yes, which reschedules the alarm a few minutes ahead rather than dismissing it.