What does Airplane Mode turn off?
Apple's support page says that Airplane Mode turns off cellular and Wi-Fi on your device, and that it turns off all radios except Bluetooth. If the airline allows it, you can turn Wi-Fi and Bluetooth on again while Airplane Mode stays on.
Apple's list of things that stop or change an alarm does not include Airplane Mode. Apple names the volume, the alarm sound, connected headphones, StandBy and a manual time change.
What works without a connection?
| Function | Airplane Mode, no Wi-Fi | Airplane Mode with Wi-Fi |
|---|---|---|
| Clock app alarm | Rings | Rings |
| Wake up alarm of a sleep schedule | Rings | Rings |
| Waker alarm that is already scheduled | Rings | Rings |
| Waker voice conversation | Needs internet | Works |
| New or changed Waker alarm | Needs internet | Works |
Does the alarm ring at the correct time after a flight?
The alarm rings at the time that the iPhone clock shows. After a flight to a different time zone, check that the clock shows the local time before you sleep.
Apple warns that a manual change of the time in Settings can affect alarms. Do not change the time by hand to adjust an alarm.
Does Airplane Mode make the alarm more reliable?
No source from Apple says so. Airplane Mode stops calls and messages that can wake you at night, and it can save battery. It does not make the alarm louder or more certain.
For the alarm sound, the same checks apply with and without Airplane Mode:
- Set the alarm volume in Settings, Sounds & Haptics.
- Check that the alarm sound is not set to None.
- Charge the iPhone for the night.
Silent mode and Focus do not stop a Clock alarm. See iPhone alarms on silent, Do Not Disturb and Focus. If the alarm shows and plays no sound, see iPhone alarm has no sound on iOS 26.
Do alarm apps work without internet?
It depends on the app and on the function. Since iOS 26, apps can schedule alarms on the iPhone with AlarmKit. An alarm that is scheduled this way is stored on the device. Functions that use a server, such as a live voice conversation or a weather report, need a connection at the moment when you use them.
Waker is an example. An alarm that you have already scheduled can ring without internet. You need an internet connection to set up or update alarms and to talk with Waker. If you sleep with Airplane Mode on, turn on Wi-Fi in Airplane Mode, or turn Airplane Mode off when the alarm rings, to have the conversation.
Common questions
Does the iPhone alarm need Wi-Fi?
No. A Clock alarm is set on the iPhone and rings without Wi-Fi and without cellular data.
Does the alarm ring when cellular data is off?
Yes. Cellular data has no function in a Clock alarm.
Can I use Wi-Fi in Airplane Mode?
Yes, if the airline allows it. Apple says that you can still use Wi-Fi and Bluetooth in Airplane Mode.
Does Waker work on Airplane Mode?
A Waker alarm that is already scheduled can ring. The voice conversation needs an internet connection, for example Wi-Fi that you turn on in Airplane Mode.
Sources
- Use Airplane Mode on your iPhone, iPad, Apple Watch, and Apple Vision Pro. Apple Support.
- How to set and change alarms on your iPhone. Apple Support, April 2026.
- Set an alarm in Clock on iPhone. iPhone User Guide, Apple.
- Scheduling an alarm with AlarmKit. Apple Developer Documentation.