Online Alarm Clock
Set an alarm for any time and keep the tab open
Keep this tab open
The alarm keeps working while the tab is in the background, but closing the tab or quitting the browser cancels it. Do not close this page until the alarm has rung.
Set an alarm for any time in the next 24 hours right in your browser — no app, no account, no downloads. Pick the hour and minute, press Set Alarm, and a live countdown shows exactly how long until it rings. If the time has already passed today, the alarm rolls over to tomorrow automatically. When it rings you can snooze for 5 minutes or dismiss it.
How to Use
- Set the time: Enter the alarm hour and minute in 24-hour format.
- Arm the alarm: Click Set Alarm — the countdown starts immediately.
- Check the sound: Click Test Sound to hear the alarm tone and confirm your volume.
- Snooze or dismiss: When the alarm rings, choose Snooze for 5 more minutes or Dismiss to stop it.
Features
- Live current-time clock with per-second updates
- Automatic today/tomorrow rollover for past times
- Exact countdown to the alarm in HH:MM:SS
- Repeating two-tone alarm sound generated locally with Web Audio
- 5-minute snooze and one-click dismiss
- Test Sound button to verify volume before you rely on it
Important: Keep the Tab Open
A browser alarm is not a replacement for a dedicated clock. The alarm only rings while this page stays open — it keeps working when the tab is in the background or the browser window is minimized, but closing the tab or quitting the browser cancels it. Some laptops also suspend background tabs when the lid closes or the machine sleeps, so keep the computer awake for important wake-up alarms. A quick Test Sound before arming confirms your speakers are on and loud enough.
Use Cases
- Wake-up backup: A spare alarm on a laptop when your phone is charging in another room.
- Meeting reminder: Set an alarm 5 minutes before a call while you keep working.
- Cooking and baking: A hands-free kitchen timer at your desk.
- Pomodoro-style breaks: Alarm yourself off the chair every hour.
- Medication reminders: A simple recurring daily cue at the same time.
Related Tools
Frequently Asked Questions
Does the alarm work if I switch to another tab or app?
Yes. The alarm keeps running while the tab stays open, even in the background or when you switch to another app. Most browsers throttle timers in background tabs slightly, so the bell may ring a few seconds late. What does not work: closing the tab or the browser entirely stops the alarm.
Do I need to install anything or create an account?
No. The alarm runs entirely in your browser with no downloads, accounts, or sign-ups. Just open the page, set a time, and leave the tab open.
What happens if the alarm time has already passed today?
The alarm automatically rolls over to the next day. For example, if it is 18:00 and you set the alarm for 07:30, it will ring tomorrow morning at 07:30. The countdown always shows the exact time remaining.
How loud is the alarm sound?
The alarm uses a repeating two-tone beep generated by the Web Audio API at your device's current volume. Use the Test Sound button to check the volume before arming an alarm, and turn your system volume up.
Can I snooze the alarm?
Yes. When the alarm rings, press Snooze to silence it for 5 minutes. After 5 minutes it rings again. Press Dismiss to turn the alarm off completely.
Does the alarm work offline?
Once the page has loaded, the alarm logic runs locally in your browser. However, if you reload the page without a connection, it may fail to load, so keep the tab open once the alarm is set.