Go to Settings/General/About and note the iPhone Model Name, then check its version compatibility from this list:
- iPhone 8 or newer, including SE 2nd and 3rd editions, you can update to 16.2
- Any iPhone series 6S and 7, and any model SE: You can update to 15.7.2
- iPhone 5S or 6: You cannot update to iOS 13 or higher; you can update only to iOS 12.5.6
- iPhone 5: You can update only to 10.3.4
- iPhone 5C: You can update only to 10.3.3
- iPhone 4S: You can update only to 9.3.6
- iPhone 4: You can update only to 7.1.2
If your phone is eligible for update, to update over the air from the phone all of these requirements must be met:
- You need at least 10 GB of free storage for iOS 16 or 6 GB for iOS 15 or lower; more is better
- You must be connected to a Wi-Fi network (and not a personal hotspot) unless it is an iPhone that supports cellular 5G (12, 13, 14 or SE 3rd edition) and has a 5G network connection
- The phone must be charged to at least 50%, and preferably plugged in so it stays above 50% during the update
- The phone must not be in Low Power Mode
- The phone must not be connected through VPN, and it may be necessary to delete any VPN apps and VPN profiles
- The phone cannot be in Airplane mode and must have a cellular data connection
- You cannot still have a beta version installed on the phone
- You cannot have a previous version that was downloaded, but not installed - go to Settings/General/iPhone Storage to look; if you find an iOS installer, delete it
If you can't meet all of them you can still update using your computer.
