Do iPhone 4 cases fit on the iPhone 5?
Absolutely NO.. The Dimensions of iphone 4/4s is - 115.2 x 58.6 x 9.3 mm (LxWxthick).Whereas Dimensions of iphone 5s is - 123.8 x 58.6 x 7.6 mmSo here between both the phones, only the Width is same, but iphone 5s has more length than 4s and iphone 5s is more thinner than the 4s. Check the actual size difference in the phone below - Now imagine, how a iphone 4 case will fit on iphone 5!! So its a NO again..
Do iphone 5 cases fit in iphone 5s?
It should seeing as they are the same dimensionally, but make note of the dual LED for the flash for the 5s vs the single LED for the 5.
Does the iPhone 5s case fit the 5c?
No. The iPhone 5S is a different size and thickness than the iPhone 5c. These were the specs released to case makers:Design Drawings Reveal Case Makers' Expectations for iPhone 5S and Lower-Cost iPhoneThe "iPhone Light" was eventually the branded as the "iPhone 5c."
Will a iphone 5c case fit the iphone 5?
No iphone 5c is thicker than iPhone 5 so the cases are not the same. iPhone 5s cases will fir 5 because they have the same design.
Will an iPhone 5 case fit an iPhone 6?
No, you can see the pics below, left is iPhone 5, right is iPhone 6.