Online alarm clock
Create an in-page alarm for today or one that repeats daily, with sound, a 5-minute snooze, and system notifications enabled only with user consent.
How to use the online alarm clock
The alarm clock is stored only in the current page’s memory and will not be uploaded or written to local storage; system notifications are requested only after you check the box and click the authorization button.
Add alarm
Choose a time based on the device’s local time zone and repeat once today or daily, and fill in an optional label.
Choose reminder method
Keep the page open to play Web Audio sounds; if needed, you can proactively check the box and request browser system notification permission.
Manage reminders
You can disable, delete, or choose to snooze for 5 minutes when it rings; after the page is restored, only missed reminders that are no more than 10 minutes late will be made up.
Limitations and Notes
- When the page is closed, the browser is frozen, the system is in deep sleep, or power-saving restrictions apply, reminders are not guaranteed and cannot be used as the sole alarm for medical, trading, or safety incidents.
- Alarms are not persisted and will be cleared after refreshing, closing, or leaving the tool page; browsers may also block sound or system notifications.
- The time is constructed using the device’s local time zone; crossing midnight, daylight saving time changes, manual clock adjustments, or an inaccurate clock may all affect the trigger time.
FAQ
Why did the alarm disappear after refreshing?
To avoid unconsented persistent records, this tool stores data only in the current page’s memory, and you need to set it again after refreshing.
Must notification permission be allowed?
Not required. It can still ring when the page is open and the browser allows audio; system notifications are an optional capability that you enable yourself.
Will it ring on time when the computer is sleeping?
Not guaranteed. After recovery, missed reminders are only made up if the delay is no more than 10 minutes; earlier reminders are skipped and the next one is scheduled.