The iPhone 5S (marketed with a stylized lowercase 's' as iPhone 5s) is a smartphonedeveloped by Apple Inc. It is part of the iPhone line, and was released on September 20, 2013. Apple held an event to formally introduce the high-range phone, and its mid-range counterpart, the iPhone 5C, on September 10, 2013.

As with the naming precedents of the iPhone 3GS and iPhone 4S, the iPhone 5S is a revised version of its predecessor, iPhone 5. The phone maintains a very similar design to its predecessor, aside from the introduction of a new home button design using a laser-cutsapphire cover surrounded by a metallic ring, Touch ID, a fingerprint recognition system built directly into the home button which can be used to unlock the phone and authenticateApp Store and iTunes Store purchases, and an updated camera with a larger aperture and a dual-LED flash optimized for different color temperatures. It also introduced the A7 dual-core processor, the first 64-bit (ARMv8-A) processor to be used on a smartphone, accompanied by the M7 "motion co-processor", a dedicated processor for processingmotion data from its accelerometer and gyroscopes without requiring the attention of the main processor. It was also the first Apple device to ship with iOS 7, which introduced a revamped visual appearance and other new features.