Last updated: July 2026
How to Use the Online Alarm Clock
Our free browser-based alarm clock is the perfect tool for when you need a loud reminder but don't want to use your phone.
- Select the Time: Use the dropdowns to set the exact hour, minute, and AM/PM you want the alarm to trigger.
- Start the Alarm: Click the "Start Alarm" button to arm it.
- Leave the Tab Open: For the alarm to work reliably, you must keep this browser tab open. Do not close the tab.
- Wake Up: When the local time on your computer matches the time you set, the alarm will ring loudly. You can hit Snooze to delay it by 5 minutes.
Important Warning About Sleep Mode
In recent years, web browsers (like Chrome, Safari, and Edge) have introduced aggressive battery-saving features. If your computer goes to sleep, or if the tab is left in the background for hours, the browser might "suspend" the tab to save memory. If the tab is suspended, the alarm will not ring.
To guarantee your alarm goes off, plug your laptop into a charger and temporarily disable your computer's sleep/standby mode in your system settings.
Frequently Asked Questions
No, most modern browsers and operating systems will suspend background tabs and audio when the computer goes into a deep sleep mode. To ensure your alarm rings, keep your computer plugged in and adjust your power settings so the screen does not turn off.
Yes! Once the page is fully loaded, the alarm clock relies on your computer's internal clock to keep time, meaning it will still ring even if you lose your internet connection.
The alarm will not ring. The timer only runs while this tab is open, so leave it active in the foreground or another visible window until your alarm goes off.
The tool currently supports one active alarm at a time. You can edit or replace the time at any point before it rings.
Yes. Every time the alarm rings, hitting Snooze pushes it back 5 minutes, and you can repeat this as many times as you need.
Not yet — the alarm currently uses a single default tone. There's no option to upload a custom sound at this time.
Yes, it runs in mobile browsers too, but mobile operating systems are typically even more aggressive about suspending background tabs than desktops, so keep the tab open and your screen on.
Check that your device's media volume is turned up before you rely on this for something important — the alarm plays through your browser's audio, which follows your system volume.