Online Alarm Clock
Free online alarm clock with multiple alarms, snooze, and a large digital display. Set alarms with labels and get audio notifications.
About Online Alarm Clock
Set Alarms Right in Your Browser
This online alarm clock turns your browser tab into a full-featured alarm. A large digital clock shows the current time, and you can set multiple alarms with custom labels, toggle them on and off, and snooze when needed.
Audio Notifications
When an alarm fires, a chime generated through the Web Audio API plays instantly. There are no sound files to download. Just keep the tab open and your volume up, and the alarm will ring on time.
Snooze and Manage
Each ringing alarm offers a snooze button (5 minutes) and a dismiss button. You can also toggle alarms on or off without removing them, making it easy to reuse the same alarm the next day.
For timing a specific duration, try the countdown timer. If you want to track work sessions, the Pomodoro timer structures your focus time with built-in breaks. Everything runs locally in your browser with no data stored on any server.
Frequently Asked Questions
Will the alarm sound if I switch to another tab?
Yes. The alarm checks the time every second using JavaScript intervals. When the alarm time arrives, it plays an audio tone through the Web Audio API. Your browser tab must remain open (not closed) and your device volume must be turned up. Some browsers may briefly delay background audio, but the alarm will fire.
Can I set more than one alarm?
Yes. You can create as many alarms as you need, each with its own time and label. Toggle individual alarms on or off without deleting them, and dismiss or snooze each one independently.
How does snooze work?
When an alarm rings, click "Snooze 5m" to delay it by five minutes. The alarm will ring again after the snooze period ends. You can snooze the same alarm multiple times if needed.
Can I switch between 12-hour and 24-hour format?
Yes. Check the "24-hour format" box below the clock display. Both the main clock and alarm times will switch to 24-hour notation. Uncheck it to return to the 12-hour AM/PM format.
Does the alarm use an external sound file?
No. The alarm tone is generated directly in your browser using the Web Audio API. No audio files are downloaded. The result is a pleasant two-tone chime that plays when the alarm triggers.