Apple is discontinuing support for a lot of old generation devices this summer.

iOS 16 will be compatible with the following iPhones

• iPhone 14 series (out of the box)
• iPhone 13
• iPhone 13 mini
• iPhone 13 Pro
• iPhone 13 Pro Max
• iPhone SE 3 (2022)
• iPhone SE 2 (2020)
• iPhone 12
• iPhone 12 mini
• iPhone 12 Pro 
• iPhone 12 Pro Max
• iPhone 11
• iPhone 11 Pro
• iPhone 11 Pro Max
• iPhone XR
• iPhone XS
• iPhone XS Max
• iPhone X
• iPhone 8
• iPhone 8 Plus

At the time of writing this article iOS 16 is available for developers only. Public Beta will be released soon.

Edit: iOS 16 is now available to everyone as OTA (Over the Air) update and IPSW files.