Online Alarm Clock
Set an alarm for any time — plays an audio alert in your browser when the time arrives. No download needed.
Current time
How to Use the Online Alarm Clock
- 1
Enter the Alarm Time
Use the time picker to select the hour and minute you want the alarm to trigger.
- 2
Click Set Alarm
The alarm is now active. Keep this browser tab open — the alarm checks the time every second.
- 3
Wait for the Alert
When your set time arrives, the alarm fires an audio tone. The page also shows an alert banner.
- 4
Dismiss
Click Dismiss to stop the alarm, or Cancel Alarm at any time to turn it off.
About the Online Alarm Clock
An online alarm clock lets you set a timed reminder directly in your browser — no app installation, no account required. Whether you need a nap alarm, a meeting reminder, or just something to pull you out of a focus session at a specific time, this free tool has you covered.
The alarm checks your local system clock every second and fires when the set time matches. The audio alert is generated using the Web Audio API — a series of alternating tones that are pleasant but attention-grabbing. The current time is displayed in real time so you can confirm synchronization.
Important: the tab must remain open for the alarm to fire. Most modern browsers allow audio to play from background tabs, but some mobile browsers may mute audio when the screen is locked. For important alarms, consider keeping the screen active or using a dedicated alarm app.
Common use cases include: nap timers (set 20-30 minutes forward), meeting reminders, cooking alarms, medication reminders, and event countdowns. The large clock display makes it easy to use as a secondary desktop clock while you work.
Unlike phone alarms, this browser alarm doesn't require you to unlock your device or navigate an app — just keep the tab open and let it run. It's particularly handy when working at a computer where your phone might be on silent.
You may also find our Countdown Timer, World Clock, and Time Zone Converter helpful.
How to Use
- 1. Set the time you want the alarm to go off.
- 2. Click Set Alarm — the current time is shown so you can confirm it is correct.
- 3. Keep this tab open; the alarm sounds in the browser when the time arrives.
- 4. Click Dismiss to stop the alert.
Frequently Asked Questions
Does the alarm work if I close the tab? expand_more
No — the alarm runs in JavaScript and requires the tab to remain open. For important events, use a phone alarm as backup.
What if my system clock is wrong? expand_more
The alarm uses your device's system clock. Ensure your device time is accurate for the alarm to fire at the right time.
Can I set a recurring alarm? expand_more
Currently the alarm fires once. After dismissing, you can set it again for the same time manually.
Will the alarm work on mobile? expand_more
Yes, on mobile browsers as long as the screen stays on and the tab is active. Screen lock may silence audio on some devices.
Is there a snooze feature? expand_more
Not currently. A snooze feature may be added in a future update.