Apple says iPhone 17 Pro and iPhone 17 Pro Max cases are not compatible with the iPhone 18 Pro and iPhone 18 Pro Max. However, hands-on testing indicates that many cases from either generation may still fit the newer phones.

The difference comes down to a small change around the rear camera area. According to Daring Fireball’s John Gruber, Apple said the camera plateau on the iPhone 18 Pro models is slightly thicker than the one on the previous generation.

What changed between the iPhone generations?

Gruber said the camera plateau measures 11.5 millimeters on the iPhone 18 Pro models, compared with 11.4 millimeters on the iPhone 17 Pro models. That one-tenth-of-a-millimeter difference is enough for Apple to give the two generations separate case-compatibility guidance.

Apple’s official position is that users should not assume an iPhone 17 Pro case will work with an iPhone 18 Pro, or that an iPhone 18 Pro case will fit an iPhone 17 Pro. The company’s guidance also means customers purchasing a new iPhone may be encouraged to buy a new case.

Do iPhone 17 Pro and iPhone 18 Pro cases fit?

In practical testing, the compatibility picture appears less restrictive than Apple’s official answer suggests. Gruber said his iPhone 17 Pro cases fit the iPhone 18 Pro models perfectly. He also found that iPhone 18 Pro cases worked on the iPhone 17 Pro models.

That testing suggests Apple-branded cases from both generations should work with both sets of Pro iPhones. Many third-party cases are also likely to be interchangeable, provided their design leaves enough clearance around the camera plateau.

Should you reuse an older iPhone Pro case?

Owners may be able to reuse an existing case rather than replacing it immediately, especially if it is an Apple case or a flexible third-party model. The small dimensional change does not appear to prevent most cases from fitting in practice.

There is still no guarantee for every accessory. Some third-party cases may be built with tighter tolerances around the camera opening, and those cases could be affected by the added thickness. Such examples are expected to be exceptions rather than the normal outcome.

For the most reliable fit, buyers should follow the case maker’s compatibility listing. But based on the available testing, the physical difference between the iPhone 17 Pro and iPhone 18 Pro camera plateaus is unlikely to make most existing cases unusable.