Alarm Clock

How to use

1. Tap one of the eight popular times under the dial, or put the hour and minute into Alarm time.
2. Add a Label if it helps to know what you set it for. Forty characters, and it shows up in the desktop notification.
3. Choose a sound and press Test sound at the volume you will actually be sleeping next to. Digital is the sharp one, Chime the gentlest.
4. Press Set alarm, or Space. The figure becomes the wait, and the line under the dial names the moment it will ring.
5. For a bedside clock, tick Keep screen awake, press Fullscreen, and plug the device in.
6. When it goes off, Snooze 5 min restarts the countdown from that moment rather than from the original time, and Stop clears the whole thing. Escape stops it too, and S snoozes.

About this tool

The alarm clock opens on 07:00. Change it to whatever you need, or tap one of the eight presets running from 5:00 AM through to 9:00 AM, then press Set alarm. It arms for the next time that hour and minute comes round, later today if that moment is still ahead and tomorrow if it has gone. Before anything is armed, the figure in the dial is the time of day. Once it is armed the figure becomes the wait itself, the ring around it drains toward the moment, and the clock moves to the line underneath, without a seconds digit ticking all night.

Four sounds sit under the dial: Beep, Chime, Bells and Digital. All of them are synthesized with the Web Audio API rather than fetched as audio files, and Test sound gives you a second and a half of whichever one is selected. Beside them, Desktop notification fires a notice when the alarm goes if you are looking at another window, and ticking it asks your browser for permission there and then. Keep screen awake takes a Screen Wake Lock so the display stops dimming while the alarm waits. Fullscreen turns the dial into a bedside face, and the tab title carries the countdown when you wander off to another tab. From the keyboard, Space arms and cancels, Escape stops a ringing alarm and S snoozes it; one checkbox turns those keys off.

A refresh will not lose your alarm. The moment it is due to ring gets written down when you set it, so reloading restores the countdown where it was, and if the time passed while the page was closed it rings as soon as you come back. Copy share link puts the time and the label into the URL, which makes a decent bookmark for the hour you get up at most mornings, and opening such a link never cancels an alarm you already have armed: its time waits in the field until you cancel. While an alarm is armed the time field and the eight times are held, so cancel it first if you want a different time.

Set at 22:47, ringing at 6:30

Getting into bed at 22:47 with a 6:30 start tomorrow: type 06:30 or tap the 6:30 AM preset, label it Flight to Delhi, pick Bells, and press Set alarm. The figure in the dial turns into the wait, 7:43:00, with the time of day on the line beneath it. Tick Keep screen awake, press Fullscreen, plug the phone in, and the dial is your bedside display for the night.

At 6:30 the bells loop, the notification carries the label, and the two buttons are Snooze 5 min and Stop. One snooze pushes the ring to 6:35; press Stop when you are actually vertical and the page goes back to being a clock.

Good to know

• All of it depends on this page staying open. Close the tab, quit the browser or let the machine properly sleep and nothing rings, and a few browsers throttle audio in hidden tabs. Keep a phone alarm as the backstop for anything you genuinely cannot miss.
• It holds exactly one alarm. Arming locks the time field and the presets until you stop it, so a second wake-up time means cancelling the first or reaching for a second device.