If your iPhone alarm is not going off, first check whether it is a regular Clock alarm or the wake-up alarm linked to a Sleep schedule. They have different controls. Then check the sound, volume and next scheduled time. Turning off Do Not Disturb is not the first fix: Apple’s built-in alarm should still sound with a Focus active.
This guide uses Apple’s current instructions, checked November 12, 2026. Settings differ between iOS versions. It does not diagnose an unverified software bug or claim that we reproduced your missed alarm.
Start with the alarm that actually failed
| What you notice | Where to start |
|---|---|
| A normal Clock alarm is too quiet | Its sound choice and the applicable alarm volume setting |
| The Sleep wake-up alarm is quiet or disabled | Change beside Sleep/Wake Up, then Alarm Options |
| An alarm works on some mornings only | The enabled switch, time and selected repeat days |
| The phone is in StandBy and does not vibrate | Choose an audible alarm sound rather than relying on haptics |
Open Clock, then Alarms. Inspect the exact entry you expected to hear, not another alarm with a similar label. Check the time, AM/PM if shown, its enabled switch and Repeat days. A weekday schedule is easy to overlook when you need an alarm on a weekend.
Check sound and the correct volume control
Apple’s Clock alarm guide separates ordinary alarms from a Health sleep schedule. For a regular alarm, edit its time and inspect Sound. Pick an audible tone for your check, then save the change. A visible alarm entry alone does not establish that it has an audible sound selected.
In Settings, open Sounds & Haptics. Apple’s iOS 27 guide shows an Alarms and Timers section: turn off Match Ringtone Volume to use its separate slider, or leave matching on if you want the linked volume. The iOS 26 guide instead directs you to the Ringtone and Alerts slider. Follow the controls your version actually displays.
Change with Buttons lets the physical volume buttons affect alarm volume. Do not assume that a loud video means the alarm setting is loud. Reopen the relevant slider after adjusting it so you know which setting changed.
For Sleep/Wake Up, inspect Alarm Options
If you use a sleep schedule, follow Apple’s wake-up alarm instructions: in Clock > Alarms, tap Change beside the wake-up entry. Scroll to Alarm Options, check that Alarm is on, choose Sounds & Haptics and adjust Alarm volume there.
When saving, distinguish Change Next Alarm Only from Change This Schedule. The first is a one-off adjustment; the second changes the recurring schedule. If tomorrow’s alarm is correct but the following mornings are wrong, review the schedule in Health rather than repeatedly fixing only the next alarm. You do not need to delete the entire schedule just to check its sound.
Silent mode, headphones and StandBy
Apple’s alarm troubleshooting article says Silent mode and Do Not Disturb do not mute the alarm. It also says a connected headset does not make alarms headphone-only: they play through the iPhone speaker as well. That makes an unrelated Focus reset a poor starting point for a sound problem.
StandBy has a specific exception: alarm haptics are disabled. If Sound is None, choose an audible sound instead of expecting vibration. If the bedside display itself is the problem, use our iPhone StandBy setup and screen guide. Calls or app alerts getting through a Focus are a different issue, covered in our Do Not Disturb troubleshooting guide.
Check the result before relying on it overnight
- Set a temporary alarm a few minutes ahead, using the sound and volume you intend to keep. Stay nearby and note whether the alarm appears, makes sound or only vibrates.
- If the time is wrong, follow Apple’s date and time guidance. Check General > Date & Time and the automatic time setting. Apple discourages changing the clock to manipulate app timers; that can affect alarms.
- If a correctly configured alarm remains unreliable, keep a separate backup for important mornings and contact Apple Support. Record the iOS version, alarm type, exact time and what happened. One successful short check does not prove every overnight alarm will work.
