12 Hour TimerFree Online Countdown
Set a timer for 12 hours with a loud alarm. Pause, add a minute, share the link.
Set time
Quick timers
Keep this tab open with volume on. Tap Test sound once to allow audio.
Online 12 hour timer
This page gives you a free online 12 hour timer. The time is already set to 12 hours, so just tap Start Timer, keep the tab open and a loud alarm rings when 12 hours are up.
A 12 hours countdown is popular for long focus block, exam preparation and slow cooking. You can pause, add one more minute or restart at any time.
Popular uses for a 12 hours timer
Long focus block
Plan a long stretch of work with a clear end.
Exam preparation
Study in long sessions with a visible countdown.
Slow cooking
Keep track of roasts, stews and slow-cooked meals.
Rest or sleep
Set a long rest and wake up on schedule.
12 hours in other units
How to use the 12 hour timer
- 1Check that the timer shows 12 hours, or change hours, minutes and seconds.
- 2Tap Start Timer and allow notifications when your browser asks.
- 3Watch the ring count down. Pause, resume or tap +1 min whenever you need.
- 4When 12 hours are over, a loud alarm rings. Tap Stop alarm or restart the same timer.
Other timers like 12 hours
12 hour timer FAQ
How do I set a timer for 12 hours?
The 12 hour timer is already selected on this page. Tap Start Timer, allow notifications if asked, and keep the tab open with your volume up. You will hear a loud alarm when 12 hours have passed.
How many seconds, minutes and hours is 12 hours?
12 hours equals 43200 seconds, 720 minutes or 12 hours.
Will the 12 hour timer keep running if I close the tab?
No, the tab must stay open for the alarm to play. You can switch to other tabs or apps, and the timer keeps its end time even if you refresh the page.
Can I pause or add time to the 12 hour timer?
Yes. Use the Pause button to stop the countdown and Resume to continue. Tap +1 min to extend a running timer, or Reset to start over.
Does the 12 hours timer work on iPhone and Android?
Yes. It works in Safari, Chrome, Edge and Firefox on iPhone, Android, Windows and macOS. It is free and needs no app or signup.