How to use the online alarm clock
If 11:21 pm is when you need to leave for work while everyone else is heading to bed, this tool sets a browser alarm that rings right through your speakers at 11:21 pm. No app, no account, just a tab that stays open until it fires.
Choose a sound before you press Start — something like a chime or a classic bell tends to work better than anything too gentle. Once it's running, the countdown happens right here in the browser, which means the tab needs to stay open in the background rather than being closed.
Compared to a phone, this alarm has one job and nothing else competing for attention — no messages, no app switching. It's free and doesn't ask for sign-up, but it only works while the tab is open and the device stays awake, so it suits daytime use at a desk better than an overnight bedroom alarm. On a 24-hour clock 11:21 pm is written 23:21, and spoken aloud it's twenty-one minutes past eleven at night. Written the Australian way that's 11.21 pm, and typed in a hurry it's often 11:21pm. Setting the alarm to 11:21 pm tomorrow morning works the same way: if the time has gone for today, the count runs through to it.
Common questions
Can I set more than one alarm at a time?
This page is built around a single alarm at a time. For multiple alarms, open a separate tab for each one and set a different time in each, keeping every tab open until it's rung.
Why use a browser alarm instead of my phone's built-in one?
Mainly for reliability against silent mode, do-not-disturb, or a phone left charging out of earshot. It's a useful backup or a desk-based alternative, though it depends on this tab staying open rather than running in the background of your phone.
Is there a cost to use this?
No, it's free, with no sign-up and no limit on how many times you set it. It just needs the tab left open until the time you've chosen arrives.
Will the alarm still ring if I close the browser tab?
No. The alarm only runs while this tab stays open — closing it, or closing the browser entirely, stops the countdown before it can ring. Keep the tab open in the background if you need it to go off later.
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