Set the alarm clock for 3:33 am

Leave this tab open — the alarm only rings while the tab stays open.

The alarm goes off in: ::

You can also try the other alarm clocks

Alarm clock for 3:31 am Alarm clock for 3:32 am Alarm clock for 3:34 am Alarm clock for 3:35 am

Going to bed for a 3:33 am alarm

Asleep by 6:18 pm — 6 full sleep cycles, about 9 hours
Asleep by 7:48 pm — 5 full sleep cycles, about 7 hours
Asleep by 9:18 pm — 4 full sleep cycles, about 6 hours

A sleep cycle runs about 90 minutes, and most people take around 15 minutes to drop off. Waking at the end of a cycle feels easier than waking in the middle of one.

3:33 am across the country

Sydney	3:33 am
Brisbane	3:33 am
Adelaide	3:03 am
Perth	1:33 am
Darwin	3:03 am

Times are worked out live in your browser, so daylight saving is already accounted for.

How to use the online alarm clock

An alarm at 3:33 am in the dead of night usually means a red-eye flight, a delivery run, or a newborn's next feed. This sets a browser alarm for 3:33 am that rings through your laptop speakers, so you don't need to fumble for your phone in the dark. Leave the tab open and it'll do the waking for you.

Set your preferred sound, press Start, then leave the tab where it is. Everything happens inside the browser — no background app, no notification pushed from a server — so an open tab is what actually makes the alarm ring at the right time.

A browser alarm like this one is handy when your phone's on silent, charging in another room, or you just don't want to unlock it and get pulled into notifications. The trade-off is honesty: it only rings while this tab stays open, so it's not a replacement for your phone alarm on a trip where the laptop lid might close. On a 24-hour clock 3:33 am is written 03:33, and spoken aloud it's twenty-seven minutes to four at night. You'll also see it written 3.33 am — a full stop instead of the colon means the same time. If you need it loud, turn the system volume up before you start: the alarm plays at whatever the device is set to.

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.