Turn up the Volume
This might sound obvious, but don’t skip over this step. It’s possible to turn up the volume with the buttons on the side of your phone without increasing the alarm volume. This is because the iPhone lets you control two completely different sets of sounds with the same buttons. For example, if you have a music streaming app open, using the buttons will control the music volume instead of the alarm volume. If your alarm volume is down or off (even if your music volume is up), you’ll have a silent alarm. Go to Settings > Sounds, or Settings > Sounds & Haptics, and make sure the RINGER AND ALERTS slider is set to a reasonable volume. Also, here is the Change with Buttons option, which you should disable to make sure the ringer and alarm volume never changes when you change the system volume with the buttons. To test the sound without waiting for the alarm to go off, open Clock > Alarm, tap Edit and select an alarm. Go to Sound and pick a ringtone from the list; if you can hear it, it should work just fine when the alarm goes off.
Reboot Your iPhone
Restarting is a common practice with technology to fix minor problems, and you can do the same with your iPhone to see if it fixes an alarm not working. To restart your iPhone, either hold down the power button until you see the power-off slider or hold down the power button while also pressing and holding the volume down button. The method you need and the location of the buttons depends on your iPhone model.
Pick a Louder Alarm Sound
Some of the iPhone alarm sounds are quieter than others, so if you have one of those chosen—and especially if the alarm volume isn’t loud, either—you might not hear it go off. Something else to watch out for is to make sure None isn’t chosen as the alarm sound for obvious reasons. Change the iPhone alarm sound from the Clock app. Open the Alarm tab, tap Edit and then choose the alarm you want to change the sound for. Go to Sound and preview the ringtones or songs to find something you think will work for you.
Check the Alarm’s Time Settings
If your alarm goes off but it’s silent, this method won’t help you. However, for iPhone alarms that are set in the app but that don’t go off at the designated time, you might not have the correct time or day set up. For instance, if your alarm is supposed to go off every day at 12:15 PM, and it worked yesterday but not today, the alarm is most likely not set up to repeat. Click Edit in the Alarm section of the Clock app, and then tap the alarm you need to edit. Go into the Repeat settings and make sure there’s a checkmark next to the days of the week for when you want the alarm to go off. Just tap a day to enable or disable the alarm for that day. If your alarm goes off at the wrong time during the day, you most likely confused AM and PM, which is surprisingly easy to do. Edit the alarm and change it to the appropriate time of day, and be sure to tap Save when you’re done.
Disable or Change the Bedtime Feature
If you have the Bedtime feature enabled on your iPhone, and the Wake time is set to the same time as another alarm, it’s possible that neither will go off. To avoid this silent alarm conflict, change the time for Bedtime or your regular alarm. To find the Bedtime settings on your phone, open Clock and tap Bedtime at the bottom. You can disable Bedtime here or slide the bell icon to a different time. If you don’t see Bedtime at the bottom of the screen, look in the Health app. Some of the sleep-related features moved to Health in iOS 15.
Delete and Remake the Alarm
For whatever reason, the iPhone might not have created the alarm correctly. Maybe it worked for a while but then stopped because of a glitch or incompatibility issue after an iOS update. Open the Clock app to the Alarm tab and delete an alarm by going to Edit and then tapping the red minus button to find the Delete option. You can also swipe left on an alarm on the Alarm tab screen to delete it. Make new iPhone alarms with the plus button on the upper right-hand corner of the Clock app.
Use Only One Alarm Clock App
If you have more than one app that can set off alarms, you might run into issues. Either stick with the default iPhone alarm clock app or disable it completely and use something else. However, be aware that third-party alarm clock apps aren’t integrated as well into your iPhone as is the one that’s built-in. This means you most likely have to keep the app open for the alarm sound to ring, as well as use the system volume (not the ringer) to adjust the alarm sound. For example, if the alarm clock doesn’t make a sound in your third-party app, open the app (so that it’s visible and on the screen) and then use the volume buttons to turn it up. This will ensure that the app’s volume is high enough to be heard regardless of the iPhone’s ringer volume. If disabling the third-party alarm clocks didn’t fix the iPhone alarm sound problem, delete them completely, reboot your phone, and then try using the stock alarm clock again.
Disable Bluetooth and Unplug Headphones
iPhone alarms should ring through the phone’s speakers, not any Bluetooth devices or headphones. However, that might not always be the case. If your phone has a software bug or behaves erratically, it might try to play the alarm through those devices if they’re actively attached to your iPhone while the alarm sounds. Depending on how you have your volume and ringer settings configured and where these accessories are located when the alarm goes off, you might end up hearing nothing. Turn off Bluetooth from Settings > Bluetooth, and unplug anything attached to the headphone jack. If the alarm works after doing those things, then be fully aware of when your alarms will go off, and make sure that your audio accessories are not connected to your phone during those times.
Update Your iPhone Software
Many users with iPhone alarm sound problems are using an outdated version of iOS. There could be a software bug in your phone that’s only resolved through an update from Apple. Update your phone wirelessly via Settings > General > Software Update, or plug it into your computer and update with iTunes. Either way, make sure you’re using the most up-to-date firmware version.
Restore Your iPhone to Factory Default Settings
Restoring your iPhone to factory default settings should be the very last thing you do to fix an iPhone alarm that has no sound because when you restore your iPhone, you’re deleting everything that’s been installed or changed on it since it was first purchased. In the process, it should also fix any alarm issues. In Settings, go to General and select Reset (Transfer or Reset iPhone in iOS 15), followed by Erase All Content and Settings. Factory resetting your iPhone resets everything, so it’s often a fix for any software-related issue. However, it’s especially helpful if your phone is jailbroken because with the thousands of tweaks you can apply to a jailbroken iPhone, it’s common for them to interfere with regular functions like the alarm clock.