Online Alarm Clock

How to set an online alarm clock

Enter the time you want the alarm to go off (in 12-hour format with AM/PM), then click Set Alarm. The alarm will fire when your device's clock reaches the specified time. A countdown timer shows exactly how long until the alarm triggers. The alarm sound plays through your browser's audio system — make sure your device volume is turned up and the tab is still open when the time comes.

Important limitations

This alarm runs in your web browser, which means it only works while the browser tab is open and your device is on. If you close the tab, put your device to sleep, or navigate away from the page, the alarm will not fire. For critical alarms (like waking up for a flight), always use your phone's native alarm app as a backup. Browser-based alarms are best suited for desk work, study sessions, cooking reminders, and other activities where you're already in front of a screen.

How the alarm sound works

When the alarm triggers, the page plays an audio file using the HTML5 Audio API. Modern browsers require a user interaction (like clicking the "Set Alarm" button) before allowing audio playback — this is a security feature to prevent websites from playing unexpected sounds. The alarm audio file is preloaded when you set the alarm, so it plays immediately when the time arrives without any network delay.

Common uses for an online alarm

• Study sessions: Set an alarm to remind yourself to take a break after a focused study period.
• Cooking reminders: Set an alarm for when your food is done — the sound plays through your speakers even if you're in another room.
• Meeting alerts: Set a 5-minute warning before an important call so you have time to prepare.
• Medication timing: Set alarms for daily medication schedules (always use a backup method for health-critical timing).
• Workout rest periods: Set a short alarm to signal when your rest period between sets is over.
• Nap timer: Set an alarm for a 20-minute power nap at your desk.

Related tools

• Countdown Timer — count down from a set duration.
• Online Stopwatch — measure elapsed time with laps.
• World Clock — see the current time worldwide.
• Meeting Planner — schedule across timezones.