The Apple Watch SE 3 features a 40mm starlight aluminum case with a matching starlight sport band in S/M size. This GPS-enabled smartwatch is powered by Apple's advanced S10 chip with 64-bit dual-core processor and 4-core Neural Engine, delivering the same performance found in the premium Apple Watch Ultra 3. The always-on Retina LTPO OLED display measures 324 by 394 pixels across 759 square millimeters, reaching up to 1000 nits of brightness and dimming to 2 nits for comfortable nighttime viewing.

Health and fitness tracking includes a second-generation optical heart sensor, temperature sensor for sleep apnea notifications, compass, always-on altimeter, high-g accelerometer, high dynamic range gyroscope, and ambient light sensor. The watch automatically tracks activity, delivers accurate fitness metrics, and enables critical safety features including fall detection and crash detection with automatic emergency services connection. GPS, Galileo, and QZSS positioning systems work together for precise location tracking, while Backtrack in the Compass app creates an automatic path of your route when off the grid.

The always-on display shows information at a glance without raising your wrist. Controls include the Digital Crown with haptic feedback, side button, double tap and wrist flick gestures, and on-device Siri processing. Connectivity features include 2.4GHz Wi-Fi, Bluetooth 5.3, GPS support, and Apple Pay. The custom Ion-X cover glass offers four times more crack resistance than previous models.

Battery life delivers up to 18 hours of normal use or up to 32 hours in Low Power Mode, with fast charging reaching 80% in approximately 45 minutes. The lightweight design weighs just 26.3 grams and fits wrists from 130-200mm. Requires iPhone 11 or later with iOS 26 or later for full functionality.