The short version: on most Android phones, an alarm app that does not ring is being stopped by battery saving. Set the app’s battery usage to Unrestricted, allow Alarms & reminders, and on Samsung, Xiaomi, OnePlus, Oppo and Huawei also change the extra background settings below.
Android phones try hard to save battery, and some manufacturers go further than Google intended by closing apps that run in the background. For most apps that is fine. For an alarm app it means the alarm may simply never go off. These steps work for any alarm app, including Fajrlock.
Menu names differ slightly between Android versions and phone models. If you cannot find an option exactly as written, use the search bar at the top of your phone’s Settings.
Step 1: set battery usage to Unrestricted
This is the fix that solves the problem on most phones.
- Open Settings → Apps and select your alarm app.
- Tap Battery (on some phones App battery usage).
- Choose Unrestricted.
If the app asks you to “ignore battery optimisation” when you set it up, allow it. It does not noticeably drain your battery; it only lets the alarm run on time.
Step 2: allow Alarms & reminders
On Android 12 and newer, apps need special permission to ring at an exact time.
- Open Settings → Apps → Special app access.
- Tap Alarms & reminders.
- Turn it on for your alarm app.
Step 3: check volume and Do Not Disturb
- Android has a separate alarm volume. Press a volume button, open the full volume panel and make sure the alarm slider is up.
- Alarms are allowed during Do Not Disturb on most phones, but check Settings → Sound → Do Not Disturb → Alarms (or Exceptions) to be sure.
- Allow notifications for the app. On many phones the alarm screen is shown through a notification.
Samsung (One UI)
- Open Settings → Battery (on older models Battery and device care → Battery).
- Tap Background usage limits.
- Make sure your alarm app is not under Sleeping apps or Deep sleeping apps, and add it to Never sleeping apps.
- Consider turning off Put unused apps to sleep.
Xiaomi, Redmi and POCO (MIUI and HyperOS)
- Open Settings → Apps → Manage apps and select your alarm app.
- Turn on Autostart.
- Tap Battery saver and choose No restrictions.
- Open the recent apps screen, press and hold the alarm app and tap the lock icon so it is not closed when you clear your apps.
OnePlus, Oppo and Realme (OxygenOS, ColorOS, Realme UI)
- Open Settings → Apps → App management and select your alarm app.
- Tap Battery usage.
- Turn on Allow background activity and, where shown, Allow auto launch.
- Lock the app in the recent apps screen as described for Xiaomi.
Huawei and Honor (EMUI, MagicOS)
- Open Settings → Battery → App launch.
- Find your alarm app and turn off Manage automatically.
- In the window that opens, turn on Auto-launch, Secondary launch and Run in background.
Google Pixel and other phones with standard Android
Steps 1 to 3 are usually enough. Also make sure Battery Saver is not set to turn on automatically overnight with restrictive options, and do not force-stop the app from its settings page: a force-stopped app cannot ring until you open it again.
Habits that break alarms
- Force stop or aggressive “cleaner” and “booster” apps stop alarms from ringing. Uninstall task killers.
- Swiping an alarm app away is fine on most phones, but not on phones with aggressive battery managers unless you locked it as described above.
- After a phone update, check the settings again. Updates sometimes reset them.
Test it before you rely on it
After changing the settings, set a test alarm two minutes ahead, lock your phone and put it down. If it rings, you are set. If it does not, restart the phone and test again.
For more detail on specific models, the independent site Don’t kill my app! keeps an up-to-date list of manufacturer battery settings.