What a Fingerprint Unlocks

The iPhone 5s shipped in 2013 with something small embedded in the home button: a fingerprint sensor called Touch ID. You pressed your thumb to unlock it, and it read you and opened. A fraction of a second. It’s hard now to reconstruct why this felt remarkable, but it did—the idea that the device recognized you rather than requiring you to prove yourself via a PIN you’d chosen because it was easy to remember, which meant easy to guess.

The A7 chip underneath was the first 64-bit processor in a consumer smartphone—a leap that mostly registered in benchmarks but made everything slightly more fluid, slightly more present. The camera gained slow-motion video at 120 frames per second, which turned out to be the kind of feature that changes what you notice. Film something ordinary at 120fps and it becomes ceremonial. Your coffee cup. A match being struck. A dog walking away.

The 5s got the proportions right in a way its successors spent years trying to walk back from. Four inches of screen in aluminum that you could actually hold in one hand without negotiating with the device. It was the last iPhone before the company decided bigger was an argument worth making. For a year or two, it was the best version of itself the phone had ever been, and people could feel it. Some still haven’t let it go.