Are iPhone 17 Pro Cases Compatible With iPhone 18 Pro? Here's What Apple Says - MacRumors

Can you use iPhone 17 Pro and iPhone 17 Pro Max cases with the iPhone 18 Pro and iPhone 18 Pro Max, and vice versa?

Apple's official answer is no, according to Daring Fireball's John Gruber. Apple said the camera plateau on the iPhone 18 Pro models is ever so slightly thicker this year. Gruber said the difference is one-tenth of a millimeter: 11.5mm vs. 11.4mm. It is a minor difference, but Apple would obviously prefer to sell you a new case.

In practice, most cases should be interchangeable. In his personal testing, Gruber said his iPhone 17 Pro cases fit the iPhone 18 Pro models perfectly, as did iPhone 18 Pro cases on iPhone 17 Pro models. So, both generations of Apple-branded cases should work with both generations of iPhones, and many third-party cases should be fine too.

Of course, there will probably be the odd third-party case that does not fit, but this is likely to be the rare exception rather than the norm.