How to use the online alarm clock
An alarm for 5:00 am is usually about catching something before the rest of the world is awake: a ferry, a flight, or a change of shift. Set the time, pick a tone, and leave this tab open. At 5:00 am it'll ring through your device's speakers until you tell it to stop.
Pick whichever sound you're most likely to actually notice, then press Start. The alarm is tied to this browser tab, so it needs to stay open. Minimising the window is fine, but closing the tab or the browser will stop the countdown before it ever rings.
The advantage of a browser alarm is volume and reliability at a desk: laptop speakers are often louder and easier to hear across a room than a phone left in a bag. The catch is that it depends entirely on the tab staying open; if the browser closes or the laptop sleeps, the alarm won't fire. On a 24-hour clock 5:00 am is written 05:00, and spoken aloud it's five o'clock in the morning. You'll also see it written 5.00 am — a full stop instead of the colon means the same time. Setting the alarm to 5:00 am tomorrow morning works the same way: if the time has gone for today, the count runs through to it.
Common questions
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.
Does the alarm work if my laptop goes to sleep?
Not reliably. If the device sleeps or the screen locks, the browser tab pauses along with it, so the alarm may not fire on time or at all. Adjust your power settings if you're relying on this over a longer stretch.