Online Alarm Clock Free — Timer, Stopwatch & World Clock
A free online alarm clock with 12 built-in sounds, snooze function, and math puzzle wake-up challenges. Set multiple alarms with custom labels — works directly in your browser tab.
How to Set an Alarm
Click "Add Alarm" and choose the time for your alarm.
Pick a label, alarm sound, and repeat schedule (once, weekdays, or custom days).
Optionally enable the math puzzle and adjust snooze settings.
Keep the browser tab open — your alarm will ring at the set time.
When the alarm rings, dismiss it or hit snooze for a few more minutes.
Set alarms, timers, and track time across the world
Features
Frequently Asked Questions
Will the alarm work if I close the browser?
No — the alarm runs in your browser tab, so the tab must stay open. Enable the Wake Lock feature to keep your screen on, and allow browser notifications as a backup alert.
How many alarms can I set?
Up to 10 alarms at once. Each alarm has its own sound, label, repeat schedule, and snooze settings.
What is the math puzzle feature?
It requires you to solve a math problem before dismissing the alarm, preventing you from turning it off while half-asleep. Three levels: Easy (addition), Medium (multiplication), Hard (square roots and multi-step).
Does this alarm work on phones?
Yes, on both iOS and Android. Keep the browser open and use the Wake Lock toggle. On iOS, the browser must stay in the foreground for audio to play.
What is the Pomodoro timer?
A productivity method: 25 minutes of focused work, then a 5-minute break. After 4 work sessions, take a longer 15-minute break. All durations are customizable.
Are the alarm sounds downloaded?
No — all 12 sounds are generated in real-time using Web Audio API. Nothing is downloaded, keeping the page fast and lightweight.
How does the sleep timer work?
It plays calming background sounds (white noise, rain, or ocean) for a set duration, then gradually fades out. Great for falling asleep before a morning alarm.
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