An online alarm clock is a web page that watches the clock and makes a noise at the time you set. There is nothing to install and no account to create, and it works on any laptop or desktop with a browser. The catch is that a web page only runs while the browser has it open. A phone alarm rings with the screen dark because the operating system wakes the alarm app; a web page has no such privilege. So the two rules that decide whether a browser alarm rings are simple: the tab has to stay open, and the computer has to stay awake.
Within those limits it is genuinely useful. A laptop on a desk makes a fine wake-up alarm, a second screen at work is a good place for a "leave for the train" reminder, and a short nap alarm is easier to set in a tab than on a phone you have put in another room.
Open the online alarm clock and press Add New Alarm. The time field takes 24-hour time, so a quarter to seven in the morning is 06:45; the card it creates shows 6:45 AM. Give it a label, tick the days it should repeat, pick one of the five sounds and press the play button next to it to hear it at the volume you chose. Leave Enable Snooze ticked if you want a five-minute snooze, then press Add.
The card shows how long is left ("in 95 minutes"). When the time comes, the page plays a pulsing tone for about five seconds and opens a window with Snooze (5 min) and Dismiss. Snooze creates a separate one-time alarm five minutes later, labelled "(Snoozed)", which deletes itself after it rings. An alarm with no repeat days rings once and switches itself off; an alarm with repeat days stays on.
Alarms are stored in your browser on this device. The same browser on the same computer will still have them tomorrow, but another browser or another machine will not.
Say you want a weekday wake-up at 06:45. Add the alarm with Mon to Fri ticked, volume 100%, and play the sound once through the laptop speakers at bedtime so you know it is loud enough. Plug the laptop in, set the display to turn off but the computer to stay awake, and leave the alarm tab in its own window so another site cannot cover it.
The page checks the clock against your alarm's hour and minute. Browsers slow down the timers of background tabs, so an alarm in a tab you are not looking at may ring a few seconds into its minute rather than on the exact second. That is fine for waking up; it is not fine for anything that needs to-the-second timing.
If you are a heavy sleeper, treat the browser alarm as the first of two. Set a phone alarm for 06:50 as a backup. The tool itself only plays the tone for about five seconds per ring, and the honest advice is not to rely on five seconds of chime alone.
The alarm is a time of day, not a countdown. For a twenty-minute nap starting at 1:40 PM, add an alarm at 14:00 with no repeat days: it rings once and switches itself off. If you would rather type "20 minutes" and skip the arithmetic, the countdown timer is the better tool. For work blocks with breaks built in, the Pomodoro timer runs 25-minute sessions; the Pomodoro guide explains the method.
Use the phone for anything that must not fail: a flight, a medication, an early start on a day that matters. Use the browser alarm for the rest: reminders while you are already at the computer, nap timers, a wake-up on a desk where the laptop is plugged in anyway, or a loud backup on a second device. It costs nothing to set and nothing to leave running, as long as the tab stays open.
Open the free online alarm clock — set the time, pick a sound, allow notifications, and leave the tab open.
No. Closing the lid puts most laptops to sleep, which suspends the page, and the alarm will not sound. Keep the laptop plugged in and set the display, not the computer, to turn off.
Yes, as long as the browser is running and the computer is awake. You hear the tone, and if you allowed notifications you also get a system notification. Background tabs get fewer timer ticks, so it may ring a few seconds into the minute rather than on the exact second.
Usually because the page had not been clicked since it loaded. Browsers block audio on pages you have not interacted with, so click or press a key once after opening the tab. Also check the system volume and that the alarm volume slider is not near zero.
They are saved in this browser on this device, so they are still there after you close and reopen the tab. They are not synced to other devices or browsers, and nothing is sent to a server.