Online Alarm Clock
Set an alarm for a time later today or tomorrow and keep this page open — it shows your current local time and plays a sound when the alarm goes off.
Everything you enter is processed in your browser and isn't sent to our servers.
How to use online alarm clock
- 1Check the current time shown at the top (switch to a 24-hour clock if you prefer).
- 2Choose the alarm time and, if you like, add a label such as “Call the dentist”.
- 3Press Set alarm. If that time has already passed today, the alarm is set for tomorrow.
- 4Leave the tab open. When the alarm rings, press Stop alarm — or Clear alarm beforehand to cancel it.
About this tool
The clock uses your device's time and time zone, so it matches the clock on your computer or phone. The alarm time is a local wall-clock time: set 07:30 and it rings at 7:30 a.m. where you are, including across a daylight saving change overnight.
When the alarm goes off, a beep (generated by your browser, not downloaded) repeats until you stop it, for up to ten minutes. The page title also changes so you can spot the alarm from another tab. On supported browsers you can tick “Keep screen on” to stop the device going to sleep while the page is open.
Important limitation: a web page can only run while the browser is open and the device is awake. If you close the tab, the device sleeps, the screen locks on some phones, or battery saver suspends the page, the alarm can't ring on time — if that happens it rings as soon as the page is active again and tells you how late it was. Use your phone's built-in alarm for anything you can't afford to miss.
Frequently asked questions
No. Web pages are paused while a device sleeps, so the alarm can't ring until it wakes up. Keep the device awake and the tab open — the “Keep screen on” option helps on supported browsers.
Related tools
Online Timer
A countdown timer with an alarm — set hours, minutes and seconds.
World Clock
Current time in cities around the world, with your own list of time zones.
Pomodoro Timer
25-minute focus sessions with short and long breaks you can adjust.
Online Stopwatch
A precise online stopwatch with lap times, accurate to 1/100 second.