iPhone case compatibility is simpler than it looks: cases almost never carry across generations, even between phones that look identical and share a screen size. Here's what determines fit, and why "nearly fits" is worse than not fitting at all.
The short answer: assume no iPhone case fits any model other than the one printed on the listing. Body dimensions, camera housing size and button placement all change between generations, and any one of the three is enough to stop a case seating properly. Genuine cross-model matches are rare.
What determines whether an iPhone case fits?
Screen size is the measurement people check, and it's the least useful one. Two phones can both be 6.1 inches and need completely different cases.
Body dimensions. Height, width and depth change in fractions of a millimetre between generations, and that's enough. The iPhone 14 is 7.80mm thick against the iPhone 13's 7.65mm. Fifteen hundredths of a millimetre, and the cases aren't interchangeable.
The camera housing. The most common single reason an old case fails. Apple enlarges lenses and rearranges modules almost every cycle to fit new sensors. A cutout that's a millimetre too small doesn't just look wrong; it physically won't seat.
Button placement. The clearest example is the Action Button, which replaced the ring/silent switch on newer Pro models. A case cut for a switch has a slot in the wrong place and the wrong shape.
Will an iPhone 14 case fit an iPhone 15?
Mostly not. Before the iPhone 15 launched, the Japanese site Macotakara tested 3D-printed dummy units against iPhone 14 cases. As MacRumors reported, small changes in chassis dimensions made the new handsets incompatible with iPhone 14 cases, with one exception: the iPhone 15 Plus fitted iPhone 14 Plus cases.
The causes were a slightly larger rear camera housing, around a millimetre of extra body size, and on the Pro models a different volume button shape. That's the pattern in miniature: several small changes, none individually dramatic, collectively fatal to fit.
One caveat: this was a pre-release test on dummy units built from leaked schematics, not on retail phones. It matched what shipped, but that's the method behind the finding.
Which iPhone models share the same case?
Genuine matches are rare and mostly historical. The iPhone 6 and 6S are the classic example: same dimensions, same layout, interchangeable cases.
| Pairing people ask about | Share a case? | Why |
|---|---|---|
| iPhone 6 and 6S | Yes | Identical dimensions and layout |
| iPhone 14 Plus and 15 Plus | Usually | No change in body size or camera block |
| iPhone 13 and 14 | No | 0.15mm thicker body, different camera module |
| iPhone 14 and 15 | No | Around 1mm larger body, larger camera housing |
| iPhone 14 Pro and 15 Pro | No | Action Button replaced the ring/silent switch |
| iPhone XS Max and 11 Pro Max | No | Camera cutout too small on the older case |
| Any standard and Pro, same year | Never | Different camera arrays and button positions |
Beyond those, treat every pairing as incompatible until proven otherwise, including the ones that seem obvious. The useful default: if the model name isn't printed on the listing, it isn't your case.
Why a loose case is worse than none
This is the part that matters and gets skipped. A case that almost fits creates three problems.
It doesn't absorb impact properly. A shell that isn't seated transfers drop energy into the frame rather than distributing it, which defeats the entire point of dual-layer construction, where the outer shell has to be in firm contact to spread the load.
It traps grit. Gaps let dust collect between case and phone, and that grit scratches the rear glass every time you handle it.
And a case that's too tight is its own problem: it can press on side buttons, causing accidental restarts or stuck volume, and it can scratch the metal rails.
There's also the magnetic issue. A magnet array needs to sit precisely over the phone's own ring. A case a couple of millimetres off gives you weak attachment and accessories that slide, which is part of why the labelling matters, covered in MagSafe compatible vs Made for MagSafe.
How do I check which iPhone model I have?
Don't identify it by looking at it. Open Settings, then General, then About, and read the Model Name field. It will say exactly which iPhone you have: "iPhone 15 Pro", not "iPhone 15".
If you're buying for someone else and can't get at their phone, photograph the back. The camera layout narrows it to one or two candidates: lens count, arrangement, and whether the module is a raised plateau or individual rings.
What we do about it
Every Casey case is cut for one specific model rather than a size band: iPhone 11 through iPhone 17 Pro Max, including iPhone Air and the 16e. That means no universal fits and no "compatible with 14/15" listings, because those compromises are exactly where the loose-fit problems come from.
The honest limitation
Precision cutting has a cost, and it lands on you rather than on us. When you upgrade your phone, your case is finished, and no amount of goodwill on our side changes that. It isn't a business model, it's the trade-off for a case that seats properly, but it's a real cost and you should know about it before checkout rather than next September.
So check your model before ordering rather than exchanging afterwards. The 30-day return window exists for when it happens anyway.
Browse by design in Best Sellers and select your model at checkout.
FAQ
Do iPhone cases fit multiple models?
Rarely. Body dimensions, camera housing size and button placement all change between generations, and any one of them is enough to prevent a proper fit.
Will an iPhone 14 case fit an iPhone 15?
Generally no. Pre-release testing found most iPhone 14 cases didn't fit iPhone 15 units, due to larger camera housings, roughly a millimetre of extra body size, and different volume button shapes on Pro models. The iPhone 15 Plus was the exception, fitting iPhone 14 Plus cases.
Which iPhone models share the same case?
Genuine matches are unusual. The iPhone 6 and 6S are the best-known example, and iPhone 14 Plus cases generally fit the 15 Plus. Standard and Pro models from the same generation are never interchangeable.
How do I check my exact iPhone model?
Settings, then General, then About, then read the Model Name field. Don't rely on identifying it by sight.
Is a slightly loose case still better than no case?
No. A shell that isn't seated transfers drop energy into the frame instead of spreading it, and the gap traps grit that scratches the rear glass.
