Online Alarm Clock
Set a free alarm for any clock time right in your browser, with no sign-up, on a computer or phone.
Online alarm clock
Your time now
Type 7, 7:30, 730 or 7:30 pm. Soonest picks AM or PM, whichever comes next.
- Free
- No sign-up
- Nothing to install
- Up to 3 alarms
- Snooze 5 or 10 min
- Kept after a refresh
Before you rely on it: keep this tab open, keep your computer or phone awake and plugged in, and turn the volume up. Sound only works after one click on this page.
Quick alarms from now
Quick alarm times
Your alarms
No alarms set yet. You can keep up to 3.
Sound and display
70%
Clock format
Your browser asks first. It only works while this tab is open.
Keyboard: F for full screen, Z to snooze 5 minutes, Esc to stop a ringing alarm. Turn shortcuts off under Sound and display.
How to set an alarm online
- Type the time in Alarm time, like 6:45 or 6:45 am. Leave the box on Soonest, or pick AM, PM, or 24-hour yourself.
- Add a label if it helps, like Leave for school or Take the bread out. It shows on screen when the alarm rings.
- Press Set alarm. The page tells you the day it will ring and how long until it does. A quick button sets an alarm in one tap instead.
- Press Test sound once to check the volume, and pick Beep, Chime, or Bell under Sound and display.
- When it rings, the clock turns red. Press Snooze 5 min or Snooze 10 min to hear it again later, or Stop to turn it off.
What the alarm needs to work
An online alarm clock lives inside a browser tab, so it's only as reliable as that tab. These are the things that stop it, and how to avoid them:
- Closing the tab or the browser. The alarm stops with it. Your alarms are saved and come back when you reopen the page, but an alarm whose time passed while the page was closed won't ring. The page will tell you it was missed.
- The computer going to sleep. A sleeping computer doesn't run web pages. Check your power settings so the computer stays awake until the alarm time, and plug in a laptop. Closing a laptop lid usually puts it to sleep.
- No click on the page yet. Browsers block sound until you click or tap a page. Setting an alarm counts. After a refresh, tap the page once when it asks.
- Volume and mute. The alarm plays through your computer's speakers or headphones at the system volume. If they're muted, you'll only get the red screen.
- Phones locking. Phones often pause a web page when the screen locks or you switch apps. Keep screen awake asks the browser to keep the display on, though the browser releases it whenever you switch away from the page.
Times that have already passed, and 12-hour vs 24-hour
An alarm is always for the next time the clock shows that time. If it's 3:00 PM and you set 9:00 AM, the alarm rings at 9:00 AM tomorrow, and the page says so right after you press Set alarm. If you only want to know the gap, count the hours left until a clock time without setting anything.
The AM or PM box decides how a time like 7:30 is read. Soonest picks whichever of 7:30 AM and 7:30 PM comes first, AM or PM uses that half of the day even if it means tomorrow, and 24-hour reads hours 0 to 23, so 7:30 is morning and 19:30 is evening. The 24-hour to 12-hour converter has a full chart if you need one.
| AM or PM box | Set at 10 PM | Set at 2 PM |
|---|---|---|
| Soonest | 7:30 AM tomorrow | 7:30 PM today |
| AM | 7:30 AM tomorrow | 7:30 AM tomorrow |
| PM | 7:30 PM tomorrow | 7:30 PM today |
| 24-hour | 7:30 AM tomorrow | 7:30 AM tomorrow |
Typing am or pm after the time, like 7:30p, always wins over the box. The alarm uses the time on your device, in the time zone shown under the clock. On the night clocks spring forward for daylight saving time, a time inside the skipped hour, like 2:30 AM in most of the US, never shows on the clock. An alarm set for it rings at the matching time after the jump, such as 3:30 AM, and the page tells you when you set it.
Questions people ask
Will the alarm go off if I close the tab or my computer goes to sleep?
No. The alarm runs inside this page, so it can only ring while the tab is open and the computer is awake. If the computer sleeps through the alarm time and then wakes with the tab still open, the alarm rings late and says how late it is. For a wake-up you can't miss, also set the alarm app on your phone.
Why do I have to click the page before the alarm can make sound?
Browsers block sound from a page until you've clicked or tapped it. Pressing Set alarm, a quick button, or Test sound counts as that click. After a refresh the page asks you to tap once more, and until you do, the alarm can only show on screen.
What happens if I set a time that has already passed today?
It rings at that time tomorrow, and the page tells you so when you set it. If you leave the AM or PM box on Soonest, typing 6:30 at 10 PM sets 6:30 AM tomorrow, because that comes before 6:30 PM.
Can I set more than one alarm?
Yes, up to three, each with its own label. They all count down at once. If two come due together, the second rings as soon as you stop or snooze the first.
How does snooze work?
When an alarm rings, press Snooze 5 min or Snooze 10 min and it rings again after that many minutes. Stop turns the alarm off. It stays in your list, and you can switch it back on for the next day.
Will my alarms still be there if I refresh the page?
Yes. Your alarms and settings are saved in your own browser, so a refresh or reopening the page brings them back. Tap the page once afterward so sound can play. If an alarm's time passed while the page was closed, it doesn't ring; the page tells you it was missed and switches it off.
Can I use this alarm clock on my phone?
Yes, but phones often pause web pages and their sound when the screen locks or you switch apps. Leave Keep screen awake on, keep the page in front, and plug the phone in. For an important wake-up, the phone's built-in alarm app is the safer choice.
Does it work in a background tab?
Yes, as long as the tab stays open. Browsers slow down scripts in tabs you aren't looking at, so the alarm sound is scheduled on the browser's audio clock ahead of time and the page checks the real clock instead of counting seconds.
Can the alarm show a notification as well as ring?
Yes, if you tick Show a notification too under Sound and display. Your browser asks for permission first, and the page never asks on its own. On a computer the notification appears even when you're in another tab or app, as long as this tab is still open. It can't arrive after the tab is closed. Most phone browsers don't let a page show notifications this way, so on a phone the page tells you and the alarm keeps using sound and the screen.
Can I type the time in 24-hour format?
Yes. Type 19:30, or switch the clock to 24-hour under Sound and display so the whole page uses it. In 12-hour mode you can type 7:30 pm, 730p, or just 7 and pick AM or PM from the box.
Sources
- Chromium project, "Autoplay policy in Chrome" (sound needs a click or tap first), chromium.org
- Chrome for Developers, "Heavy throttling of chained JS timers beginning in Chrome 88" (background tabs slow down timers), developer.chrome.com
- MDN Web Docs, "Screen Wake Lock API" (the lock is released when the page is hidden), developer.mozilla.org
- web.dev, "The Screen Wake Lock API is now supported in all browsers", web.dev
- NIST, "Daylight Saving Time (DST)" (US clocks skip from 2:00 to 3:00 a.m. on the second Sunday of March), nist.gov
- MDN Web Docs, "Using the Notifications API" (permission is asked after a click, and most phone browsers can't show page notifications), developer.mozilla.org
More timers and time tools
- Online timerCount down a set number of minutes instead of waiting for a clock time.
- StopwatchCount up with laps and notes.
- Hours from nowSee what time it will be in a few hours before you set an alarm.
- Military time converterSwitch between 24-hour and 12-hour times.
- How long until a timeSee the hours and minutes left before your alarm time.
This alarm clock is part of TimerCalculator.com and was built by Cedrick Reese. Each alarm is stored as an exact date and time, so it rings by the real clock rather than by counting seconds, and its sound is booked ahead on the browser's audio clock and re-booked every half minute so it stays on time. Before launch, a browser automation script fast-forwarded a simulated clock through alarms set a few minutes out, alarms kept across a page refresh, an alarm that crossed midnight, a time that had already passed that day, and a time inside the hour skipped when clocks spring forward. Your alarms and settings stay in your own browser and are never sent anywhere.