iPhone alarm not working: how to fix it
Work through these steps in order. In the vast majority of cases you are back on track within two minutes, without resetting your phone.
Step 1: the ringer volume
Go to Settings, Sounds & Haptics, and raise the Ringtone and Alerts slider. Do it here, not with the side buttons: those control media volume as soon as sound is playing, which is separate from the alarm.
Step 2: is the alarm actually on
Open the Clock app and check that the toggle next to your alarm is green. While you are there, check AM and PM if you use a 12-hour clock, and whether it repeats on the right days.
Step 3: alarm sound and sleep schedule
- Tap your alarm and check the Sound setting. If it is None, it only vibrates.
- If you use Sleep or a sleep schedule, that alarm is separate from your regular alarms. Turn it on or off there.
- A Focus mutes notifications, but not the Clock app's alarm. If your third-party alarm app fails, that is exactly the cause.
Step 4: when it is the app
If you use a third-party alarm app and it does not go off, that is usually not a bug but the design: such apps lean on notifications, and those get muted by silent, Focus and your notification volume.
Since iOS 26 an app can set a real alarm through AlarmKit, treated like the system alarm. NanoTimer does that.
An alarm that does go off
NanoTimer sets a real AlarmKit alarm: through silent and Focus, ringing until you stop it. Free, no ads.
Frequently asked questions
- My alarm vibrates but makes no sound.
- Then the alarm sound is set to None, or your ringer volume is all the way down. Check Settings, Sounds & Haptics first, then the alarm's own Sound setting.
- Do I need to restart my iPhone?
- Rarely. Work through the steps above first; in practice it is almost always volume, a switched-off alarm or a sleep schedule.
- Would a different alarm app help?
- Only if it sets a real system alarm. An app that leans on notifications has exactly the same problem. NanoTimer uses AlarmKit (iOS 26 and up).