Online Alarm Clock — Free, In-Browser, No Install
An online alarm clock that runs entirely in your browser tab — no app, no account, no sign-up. Open the page, set the time, and keep the tab open until the alarm goes off. Your selection is remembered on return visits via localStorage.
Pick a sound from the catalog (or stay with the default), set a title for context, and toggle repeat if you want a fallback reminder. The main display is fullscreen-friendly for bedside use; mobile and desktop are equally supported.
The alarm triggers while this tab is in the foreground. If your device is locked or the tab is throttled, the alert may be delayed — see the FAQ below for critical wake-up backup suggestions.
A browser alarm earns its keep at a desk: you are already working on this screen, the speakers are already on, and your phone may be in another room or on silent. It also suits shared spaces — a kitchen laptop, a studio, a classroom projector — because there is nothing to install and nothing to sign in to.
Reliability checklist: keep this tab open (a pinned tab survives most restarts), keep the device awake, and unmute the output device. Browsers can block automatic sound until you have interacted with the page, so press Set Alarm and try the alert once — after that the sound is allowed. For a wake-up you absolutely cannot miss, keep a phone alarm as a second line of defense.
Frequent times get their own pre-armed pages: set an alarm for 12:45 PM to end a lunch break, or for 10:45 AM as a late-morning reset. The editor is identical — sound, title, repeat — with only the time already filled in.
Frequently asked questions
- How do I set an alarm on onetimer?
- Open /alarm, click Set Alarm (or Edit), choose a time using the 12/24-hour toggle, optionally set a title and a sound, then click OK. The countdown runs in this tab until the chosen time. To dismiss, click Stop on the alert overlay or press Esc.
- Will the alarm work if my computer sleeps?
- The alarm needs your device awake with this tab open. For critical wake-ups, disable sleep mode, keep the laptop plugged in, or use a dedicated alarm device as backup. The on-screen alert still appears when you return even if the audio was missed.
- Can I change the alarm sound?
- Yes. Open the alarm editor, switch the Sound dropdown to any of the 24 ringtone options grouped by Classic & Bells, Digital & Modern, Musical, Nature, Urgent & Loud, and Gentle & Fun. Use Try Alert to preview before relying on it.
- Is this alarm clock free?
- Yes. All alarm features — sound catalog, 12/24-hour toggle, fullscreen display, share/embed, repeat — are free with no subscription and no account.
- Does the alarm work on mobile?
- Yes. The alarm module is mobile-friendly out of the box — main display, editor, sound picker, and alert overlay all adapt to small screens. On most mobile browsers, the tab needs to stay open for the audio to fire reliably; closing the tab stops the alarm.
- Why didn't the alarm sound?
- Usually the browser blocked autoplay, the tab was closed, the output device was muted, or the computer went to sleep. Interact with the page once (Set Alarm, then Try Alert) so sound is allowed, keep the tab open, and check the device volume.
- Can the alarm repeat daily?
- Yes. Open the alarm editor and turn on repeat — it re-arms itself for the same time each day. Alarms are saved in this browser's local storage, so they stay on this device.
- Can I set more than one alarm?
- Yes. Add as many as you need — each alarm keeps its own time, label, sound, and repeat setting, and they all run while the tab is open.