iPhone alarms are usually silent and do not vibrate.

Make sure your display standby settings are turned off. If it is on, your alarm will automatically snooze itself when the display times out. So if you’re a heavy sleeper and don’t hear your alarm within the first 20 seconds or minute, you’ll miss the alarm.

This solved the puzzle of why it was getting quieter after 2 seconds when I was testing the alarm (setting it for 1 minute later, then watching it while waiting for it to go off to hear how loud it was—because the new tones are too soft and the song I set would't actually play).

On the iPhone 15 I ended up going to the bottom of the list of tones to select "Classic > " to get the list of classic tones that are abrupt enough to actually wake me up (I'm a very deep sleeper).

Maybe it’s your Bluetooth automatically connecting to something. Otherwise mine is acting strange too.

Go to the "Alarms" app and you'll see the snooze option at the bottom

I have the same issue I drive trucks and often wake up to drive early morning like 1 to 3 am… I’ve had this happen to me twice now I thought I was the only one… was late twice because my alarm made no sound… I often sleep with my wife on the phone I don’t know if that’s the issue but it’s never been a problem before now

At this point, I’m seriously considering giving up on this so-called “new” iPhone 15 and either going back to my iPhone 13 or to an android. I’m not even sure if it’s the phone or the iOS upgrade. This Alarm issue is so irritating and impossible to comprehend for Phone that costs so much money!!!!!

I really should not have to play Russian roulette every time I go to sleep and I have an important event to wake up for, or be an IT specialist just to ensure that my alarm functions the way it should.

This is happening to me a lot as well. I also have an Apple Watch that charges at night and is always on the charger when this seems to happen. I have missed some pretty important stuff a few times because of this. I’m just going to go back to the old school alarm clock. Ridic.

Wow. this is quite ridiculous to be set as default. I think your post just made my hisbands problem of missing alarma crystal clear. He wakes up, looks at it and because he's half asleep and thr darn alarm geta quiet he goes back to sleep confused. Thank you!!!

I’m running into this currently and quite frankly it’s getting my and my family’s nerves my dad isn’t very happy that I’m missing out on the first classes of the day and this is getting a little annoying

SERIOUSLY! iPhone alarm issues

with or without watch sleep tracking, With or without silent mode activated, With or without “stop playing” timer for audio, with or without wireless Apple MagSafe charger phone in landscape or portrait and With or without wearing air-buds. If I set a wake-up alarm I WANT AN ALARM TO SOUND! Plain and simple.

Which means that if you accidentally happens to need 3-4 alarms one morning because of night duties in the home you need to set several alarms with 5-10 minutes in between?

I done this, but the alarm is silenced by any movement, new alarm or SMS coming in at the same time.

On top, if alarm starts off loud, it goes very silent or totally silent within 1 second.

For $2,0000+ that's not something I think would be a feature in a very expensive (for ordinary people very expensive). I believe Apple has a work around, but chose silent alarms as a built-in feature?

Tested on one regular daily alarm. Finally ear-damaging sound. Perfection.

Monday is the ultimate test. Continuous alarms for 90 minutes to track medical procedures for my daughter.

Thank you very much @Asirae

Wishing you a really pleasant weekend

One of these suggestions helped I think. But still feels like a design problem more than user error. If I set an alarm, I want to be notified. Period. Unless I set the alarm sound to None, it should go off. I should not have to check my ringer volume, do not disturb setting, or sleep focus as well. It’s also hard to understand how all these features interact generally. Please work on this Apple. Sincerely, a UX Researcher.

This is the most ridiculous response. An alarm should just work! Why would anyone want to set an alarm and NOT have it go off unless we change a bazillion settings?! Out of curiosity I followed these steps and half of them do not exist. Personally my alarm has been having issues since the recent updates.. smh

I have missed exams and other important meetings because of this problem. How is the official Apple response: "Go and change 20 hidden settings, where you have to turn on all your sounds." I don’t want to have notification sounds or others on, but i want my alarm to make an ALARM. How is there not just an option to keep your sound off, but the alarm at full blast. For one of the largest companies on earth to not be able to create a functioning and simple alarm is ridiculous. I just had enough and bought a classic alarm clock with bells for 10€. How is a >1000€ phone unable to do this?