Android alarm not going off? The settings that fix it, brand by brand

You set the alarm, you checked the time, and it still didn't ring. On Android, that is rarely the alarm app's fault and almost never bad luck. It is usually one of a handful of phone settings, and most of them come from the same place: your phone trying to save battery.

This guide covers the checks that apply to every Android phone, then the extra battery settings on the brands that are most aggressive about them. It works for any alarm app, Waky included. It takes about five minutes, and you only have to do it once.

Why Android alarms fail at all

Android phones stretch battery life by pausing apps you are not using. For most apps that is fine. For an alarm app, it can mean the alarm is quietly held back until you open the phone, which is exactly what you don't want at 6:30.

Some manufacturers go further than Android itself does. Their battery tools put apps to sleep after a few days without use, stop them starting in the background, or close them when you clear your recent apps. Nothing warns you when this happens. The alarm simply stays quiet.

Five checks for every Android phone

Start here, whatever phone you have.

• Set the app's battery use to Unrestricted. Open Settings, go to Apps, pick your alarm app and open its battery page. Choose Unrestricted (on some phones it's called "Don't optimize" or "No restrictions"). This is the single most important setting in this guide.

• Allow notifications for the alarm app. On Android, the alarm screen that wakes you arrives as a notification. If notifications are off, the alarm may sound with nothing on screen to switch it off.

• Turn up the alarm volume, not just the ringer. Android has a separate volume for alarms. Open Settings, then Sound, and check the Alarm volume slider specifically.

• Check Do Not Disturb. Alarms are normally allowed through Do Not Disturb, but that can be changed. In the Do Not Disturb settings, make sure Alarms are allowed.

• Don't force-stop the app. Tapping Force stop in an app's settings cancels its alarms until you open it again. On some phones, clearing all recent apps does something similar, which is why several brands below let you lock an app in place.

If your phone is a Google Pixel, Motorola or Nothing phone, these five checks are usually all you need.

Samsung Galaxy

Samsung's battery tools put apps to sleep when you haven't opened them for a while, and an alarm app is exactly the kind of app you don't open every day.

• Unrestricted battery: Settings > Apps > your alarm app > Battery > Unrestricted.

• Never put it to sleep: Settings > Battery > Background usage limits. Add your alarm app to Never auto sleeping apps, and consider turning off Put unused apps to sleep.

Menu names shift between One UI versions. If you can't find a setting, use the search bar at the top of Settings and type "sleeping apps". It's also worth checking again after a big software update.

Xiaomi, Redmi and POCO

Xiaomi's software is among the strictest about background apps, so there are a few more switches.

• Autostart: open your alarm app's App info page (Settings > Apps > Manage apps > your alarm app) and turn on Autostart.

• Battery saver: on the same page, open Battery saver and choose No restrictions.

• Lock it in recents: open the recent apps view, then long-press or pull down on your alarm app's card and tap the lock. Locked apps aren't closed when you clear the list.

If a menu looks different on your version, search Settings for "autostart" and "battery saver".

OnePlus, OPPO and realme

These phones share a lot of their battery settings.

• Background activity: Settings > Apps > App management > your alarm app > battery usage. Turn on Allow background activity.

• Auto launch: on the same screen, turn on Allow auto launch if you see it.

• Lock it in recents the same way as above, if your phone offers it.

Search Settings for "background activity" or "auto launch" if the path is different on your phone.

Test it once, properly

Changing settings is only half the job. The part people skip is the test that matches real life.

1. Set an alarm for three or four minutes from now.

2. Lock the phone and put it down. Don't open the app again.

3. Wait for it to ring, at the volume you actually sleep with.

If it rings on a locked phone you haven't touched, you're set. If it doesn't, go back through the brand section above: one of those switches is almost always the cause.

After updates, check again

System updates occasionally reset battery settings or add new ones. If an alarm that used to work suddenly doesn't, the Unrestricted setting and the brand-specific switches are the first things to look at.

The short answer

When an Android alarm doesn't go off, the phone is usually saving battery at the worst possible moment. Set the alarm app's battery use to Unrestricted, allow its notifications, check the alarm volume, and on Samsung, Xiaomi, OnePlus, OPPO or realme, switch off the extra sleep and autostart limits. Then test it once with the phone locked. Five minutes now saves a late morning later.