The iPhone X was the first smartphone to use 3D facial recognition marketed as Face ID for unlocking.
Released in November 2017, the iPhone X used Apple’s TrueDepth camera system, housed in the front notch. An infrared camera, infrared illuminator, and dot projector built a depth-aware map of the user’s face, allowing Face ID to work in darkness and distinguish facial structure rather than relying only on a conventional selfie image.
Face ID replaced Touch ID as Apple’s primary biometric-unlocking system on the iPhone X. Apple said the system used on-device processing and a neural-network-based facial model, with attention detection designed to check that the user was looking at the phone.
Earlier phones offered face unlock, including some Android models, but many relied on ordinary front-camera images and were less resistant to spoofing. The iPhone X’s defining distinction was combining facial recognition with dedicated 3D depth-sensing hardware.