What's particularly interesting is how Apple has made iOS 15 compatible with all iPhones that run iOS 14. Similarly, iPadOS 15 runs on all iPads that could handle the 14th-generation software.
This means iOS 15 works on the following smartphones:
All models of iPhone 12
All models of iPhone 11
iPhone XS and XS Max
iPhone 8 and 8 Plus
iPhone 7 and 7 Plus
iPhone 6S and 6S Plus
iPhone SE 1st and 2nd generation
iPod Touch 7th generation
With the iPhone 6 unable to run iOS 14, it was assumed the iPhone 6S, which arrived back in 2015, would fail to make the grade with iOS 15. But this is not the case, and this fall a smartphone that is six years old will be able to run Apple's latest software.
iPadOS 15 is due out this fallApple
There is similarly good news with the iPad family, as these models will work with iPadOS 15:
All models of iPad Pro
iPad generation 5, 6, 7 and 8
iPad Mini 4 and 5
iPad Air 2, 3 and 4
The real surprise here is the iPad Air 2, which landed way back in 2014, making it seven years old yet still capable of running iPadOS 15 when it arrives in the fall.
2021 Apple 12.9-inch iPad Pro (Wi‑Fi, 128GB) - Space Gray