The three failures, in order of how often they happen

Almost every “my alarm didn't go off” is one of three things, and they need completely different fixes.

  1. It never rang. Toggled off, wrong day, wrong am/pm, dead battery. Boring, common, and entirely preventable by the checks above.
  2. It rang too quietly to wake you. Volume slider, soft surface, covered speaker, Bluetooth. Also preventable, and the one-minute test catches all of it.
  3. It rang, you turned it off, and you went back to sleep. This is the big one, and nothing on this checklist helps with it.

If you have been through this list twice and the alarm demonstrably rings, you have failure three, not failure one. That is a different problem with a different answer: why you turn off your alarm without remembering.

Louder is usually the wrong fix

If you are switching the alarm off without remembering it, the alarm was already loud enough to rouse you. The failure happened after that, at the dismissal, and volume does nothing about it. Turning it up just makes the mornings you do wake up worse.

Volume only helps if you genuinely are not being woken at all, and in that case the more likely cause is sleep debt rather than decibels. More detail in how iPhone alarm volume works.

When this is worth raising with a doctor

Everything on this page assumes you are getting enough sleep and still struggling to wake. If you sleep a full night and still wake unrefreshed, feel sleepy during the day, or someone has told you that you snore loudly or stop breathing in your sleep, that is worth a GP appointment rather than another app. The NHS pages on excessive daytime sleepiness and sleep apnoea describe what to look for. Mornio is not a medical product and cannot diagnose or treat anything.

The night-before routine

For anything that genuinely matters, a flight, an exam, a first shift:

The full version is in the night-before checklist.