Apple’s official answer on whether iPhone 17 Pro cases fit the iPhone 18 Pro is no. Real-world testing tells a different story, and the gap between the two comes down to a change smaller than the width of a human hair.
As per Daring Fireball’s John Gruber, Apple confirmed the camera plateau on the iPhone 18 Pro models is very slightly thicker than last year’s. Gruber pegged the exact difference at one-tenth of a millimeter, 11.5mm versus 11.4mm.
Apple’s Official Answer Is No, Over a Tenth of a Millimeter
A change that small would normally be irrelevant to a case’s fit, but Apple has an obvious reason to prefer people buy a new case anyway. This isn’t the first time the two generations’ case compatibility has come up either. OtterBox claimed before launch that iPhone 18 Pro would fit inside iPhone 17 Pro cases, based on the specs Apple had shared with case makers ahead of release.
Gruber’s Own Testing Shows the Cases Are Interchangeable
Gruber tested it himself once both phones were in hand. His iPhone 17 Pro cases fit the iPhone 18 Pro models without issue, and his iPhone 18 Pro cases fit iPhone 17 Pro models equally well. Both generations of Apple’s own cases appear interchangeable in practice, and most third-party cases should be fine too, though the odd exception with unusually tight tolerances is still possible. Gruber wrote:
The iPhone 18 Pro and Pro Max are nearly identical to the 17 Pro and Pro Max in size and shape. Per Apple’s own specs, they’re precisely the same width, height, and thickness. In my personal testing, 17 Pro cases fit 18 Pro phones perfectly, as do 18 Pro cases (included from Apple in my review unit kit) on 17 Pro phones. I asked Apple if they’re stating that 18 Pro models are case-compatible with the iPhone 17 Pro, and they are not, because the 18 Pro camera plateaus are slightly thicker this year. I measured with a digital caliper and the difference is one-tenth of a millimeter: 11.5mm vs. 11.4mm. So Apple has raised the plateau guard lip on its own 18 Pro cases by one-tenth of a millimeter. I say that’s close enough to declare that you can use 17 Pro cases on 18 Pro iPhones and vice-versa.
Anyone still shopping for a case rather than reusing an old one has a full rundown of the best iPhone 18 Pro cases from Spigen, Nomad, ESR, Pitaka, and others to choose from.
Our Take
A tenth of a millimeter is a rounding error in manufacturing terms, and Apple almost certainly knows most cases will fit fine regardless of what the official line says. Stating incompatibility anyway is the safer legal and marketing position for Apple to take, since it avoids promising a fit it can’t guarantee across every single third-party case on the market. For anyone with a case they already like, the practical answer is to try it before buying a new one.
