Online Alarm Clock
Set the time you want to be woken and register the alarm. As long as this tab stays open, a sound will play at that time.
How to use the Online Alarm Clock
- Set the Alarm time field to the hour and minute you want the sound to start.
- Press Set alarm. The line underneath confirms the time now registered.
- Leave this tab open and unmuted, then press Stop alarm to silence it.
The alarm fires on the exact minute, once
Every second the page compares the clock with the time you registered, and starts the sound only on the tick where the seconds read zero. Browsers slow timers in background tabs, so keeping this tab visible is the dependable way to catch that tick.
Nothing is saved, and the sound is made live
The alarm time is held in the page only, so a reload or a closed tab clears it, and there is no daily repeat. The sound is a 1000 Hz tone the browser generates, about a third of a second long, repeated until you press Stop alarm.
Frequently asked questions
Do I need to keep the tab open?
Yes. The alarm runs in this browser tab, so leave it open. You can switch to other tabs and keep working.
I cannot hear the alarm.
Check that the tab is not muted and that your device volume is turned up. Some browsers also block sound until you interact with the page, so press a button once after loading.
Can I set more than one alarm?
No. Pressing Set alarm with a new time replaces the previous one, since only one is held. For a second alarm, use another tab.
Is there a snooze button?
No. Stop alarm is the only control once it rings, and it cancels the alarm rather than delaying it, so set a new time to be woken again.
Will it ring with my phone screen off?
Do not count on it. Phones suspend background tabs to save power, which stops the timer that watches the clock. Use the device's own alarm app when it matters.