The difference is largely dominated by the phone's recent camera bump and USB-C switch (two small changes from the 14 series that most buyers are unaware of, which effectively prohibit universal-fit cases).
The short answer:
The best iPhone 15 case fits the device (standard, Plus, Pro, or Pro Max) correctly around where the camera cutout and charging port appear, utilizes MagSafe-approved magnet placement if you're going to charge your phone wirelessly, and matches up with your real-world drop risk instead of simply providing something that looks like a better protection solution.
Camera and port alignment matters more than it used to.
The iPhone 15 line switched to USB-C, which sounds relatively trivial, but the cutouts of ports that worked fine for Lightning-based iPhone 14 cases don't always come out so cleanly. A case built specifically for the 15 series avoids the loose or slightly misaligned port issue some early universal cases had.
Material choice follows the same logic as any iPhone case.
Silicone and TPU give you grip and shock absorption for daily carry. Polycarbonate holds up better against scratches over time. Leather ages well and looks genuinely premium but adds less impact cushioning. Consumer Reports' phone accessory testing has consistently found that material choice affects drop survival more than most buyers expect going in.
Don't skip checking MagSafe alignment specifically.
Even if you don't use MagSafe today, more accessories (car mounts, wallets, power banks) are built around it every year, and a properly aligned case now saves you from needing to rebuy later.
Check our full iPhone 15 case selection for options with verified fit across all four 15-series models.
FAQ
Q. Does the iPhone 15 need a different case than the iPhone 14?
Yes, the two phones are similar in many respects. Still, different enough that iPhone 14 cases don't generally work with either model in the 15 series, especially around the charging port and camera cutout.
Q. Do all iPhone 15 cases support MagSafe?
No. MagSafe compatibility depends on a precisely placed magnet ring inside the case, which not every case includes even if it's magnetic. Check that the listing specifically confirms MagSafe compatibility rather than assuming.
Q. Is a silicone or polycarbonate case better for the iPhone 15?
Ultimately, it's all about how far you think you'll push your phone because silicone offers better everyday grip and shock dispersion against drops and slides, while polycarbonate will resist more scratches and scuffs over a span of months.