Can an iPhone 12 function in Airplane Mode?

Not for phone calls as Airplane Mode turns off your cellular radio, but you can use Wifi and do most other things through Wifi. See this --> Use Airplane Mode on your iPhone, iPad, iPod touch, Apple Watch, and Apple Vision Pro - Apple Support

Once you're in Airplane Mode, if you manually turn Wi-Fi back on and connect to a network (like in-flight Wi-Fi or airport lounge Wi-Fi), you can use:

1. Here's how you can make it work:
   1. Airplane Mode ON – disables cellular by default
   2. Turn Wi-Fi ON manually
   3. To check or enable: Settings > Cellular > Wi-Fi Calling > Turn On --(or Settings > Mobile Data > Wi-Fi Calling, depending on region)
2. If your carrier supports Wi-Fi Calling and it's enabled in your iPhone settings, then yes—you can: If Wi-Fi Calling is set up, your phone will route calls and texts through the Wi-Fi network
   1. Make and receive phone calls
   2. Send and receive SMS/MMS
3. WhatsApp, iMessage, Telegram (for texts, voice, or video calls)
4. Email (Gmail, Outlook, etc.)
5. Safari for Browsing
6. Social media (Instagram, Facebook, Twitter/X)
7. Streaming (Netflix, YouTube, Spotify, etc.)

Just remember:

• You still can’t make regular phone calls or send SMS texts, because cellular is off.
• If you turn Bluetooth back on too, you can use AirPods or smartwatches.

So yes, online apps are fully functional with Wi-Fi, even in Airplane Mode—your iPhone just thinks it’s flying first class.