iPhone alarm not going off? Every fix, in order

Four causes account for the overwhelming majority of silent iPhone alarms. Work through them in this order. Each takes under thirty seconds and rules out a whole category of problem.

1. 1Check ringer volume, not media volume. Go to Settings → Sounds & Haptics and drag the Ringtone and Alerts slider up. The side buttons usually change media volume, not the ringer, so the slider can sit at zero while everything else sounds fine.
2. 2Disconnect Bluetooth. If your phone is still paired with headphones, earbuds in a case, a car or a speaker, the alarm may be playing through that device instead of the phone. Turn Bluetooth off overnight and see whether the alarm returns.
3. 3Confirm AM versus PM. Open the Clock app and read the alarm carefully. An alarm set for 6:40 PM looks almost identical to 6:40 AM at a glance, and it is the single most common false alarm-failure.
4. 4Check Focus modes. Settings → Focus → Sleep. Alarms are supposed to bypass Focus, but a custom Focus with an aggressive schedule can still suppress the alert on some iOS versions. Temporarily disable all Focus modes to test.

These are less common but each one genuinely silences alarms. Work down the list.

1. 1Set the alarm sound again. Open the alarm, tap Sound, and select a tone even if one already appears selected. If the sound is set to None, or to a song no longer on the device (a track removed from your library, an unavailable Apple Music file), the alarm fires with no audio at all.
2. 2Turn off Attention Aware Features. Settings → Face ID & Passcode → Attention Aware Features. When this is on, the iPhone lowers alarm volume if it detects you looking at the screen. It can misfire and start the alarm far quieter than expected.
3. 3Restart the phone. A restart clears the scheduling daemon and resolves a surprising share of one-off failures. Hold the side button and a volume button, slide to power off, wait ten seconds, power back on.
4. 4Update iOS. Several point releases across recent years have shipped fixes for alarms firing silently. Settings → General → Software Update.
5. 5Check Do Not Disturb While Driving. If it triggers on a schedule or by motion, alerts can be suppressed in ways that surprise people.

There is a recurring iOS defect in which alarms fire on schedule: the alarm appears in the Clock app as having gone off, and the phone may even vibrate, but no sound plays. It is not user error, and it has reappeared across multiple iOS versions rather than being fixed once.

When it hits, the practical mitigations are: keep iOS current, avoid custom song-based alarm sounds in favour of built-in tones, and do not rely on a single alarm for anything genuinely important.

Swapping to an alarm app does not automatically make things more reliable, and can make them worse. It depends entirely on how the app schedules the alarm.

• Apps that schedule alarms in JavaScript or in their own background process depend on that process still being alive at the right moment. The operating system is free to kill it, and does.
• Apps that fetch anything at ring time (ads, remote config, a sound file) fail when the network is down.
• Apps that rely on a standard notification rather than a real alarm inherit every Focus and volume rule that applies to notifications.

Roosta registers alarms with the operating system rather than scheduling them itself, and nothing on the alarm path touches the network. That is why it still rings when the app has been swiped away, the phone has restarted, or there is no signal at all. It is also why we can be specific about this rather than promising reliability in general.

The Clock app contains two independent alarm systems, and mixing them up produces a failure that looks inexplicable until you know about it.

The Alarm tab holds ordinary alarms. The Sleep tab holds a sleep schedule with its own Wake Up alarm, which has a separate sound, a separate volume and a separate on/off state. Editing one has no effect on the other.

• A Sleep schedule that has been turned off, or paused for a day, removes a wake-up you may still believe is set.
• Changing the sound on the Alarm tab does not change the Wake Up sound, and the Sleep alarm draws from a shorter, deliberately gentler list of tones.
• The Wake Up alarm respects the Sleep Focus schedule around it, so changing your sleep schedule can move it.

If an alarm you were certain about did not ring, open both tabs and check which one you actually set.

Alarm volume follows the Ringtone and Alerts slider, not the side buttons. The side buttons normally change media volume, so the ringer can sit at zero while music, video and games all sound completely normal. This is the most common cause of a silent iPhone alarm, and it is invisible unless you go looking for it.

If the ringer volume keeps ending up at zero, Change with Buttons is why. With it on, the side buttons adjust the ringer too, so anything that knocked the volume down during the day, including a phone pressed against something in a bag, carries into the morning.

Attention Aware Features is the subtler one. When it is on, the iPhone lowers alert volume if the front camera thinks you are looking at the screen. In a dark room, facing a pillow, it can misjudge that and start the alarm far quieter than expected.

Everything above is troubleshooting. If the wake-up genuinely matters, it is worth designing for failure rather than only fixing the last one.

1. 1Use a built-in tone rather than a song. A song depends on a file still being present and, if it streams, on a network at 6am.
2. 2Keep iOS current. Several point releases have shipped fixes for alarms firing silently, and the defect has reappeared more than once.
3. 3Turn Change with Buttons off so the ringer volume cannot drift during the day.
4. 4Test with the phone locked and face down. Testing with the screen on and the app open hides exactly the failures you are trying to find.
5. 5For anything you cannot afford to miss, set a second alarm on a different device. This is not a lack of confidence in the phone; it is what you would do for any single point of failure.

And if the alarm rings reliably but you turn it off and go back to sleep, none of this is your problem. That is a different failure with a different fix, and it is the one Roosta was built for.