Apple Watch Series 9 (45 mm, GPS, aluminium) / Apple Watch Series 6 (40 mm, GPS)

Apple Watch Series 9 (45 mm, GPS, aluminium): 45 mm aluminium case, GPS model; Pink, Midnight, Starlight, Silver and (PRODUCT)RED. The 41 mm, GPS + Cellular and stainless steel (sapphire crystal) versions differ in size and materials.

Apple Watch Series 6 (40 mm, GPS): Apple Watch Series 6, 40 mm aluminium case, GPS (2020). The 44 mm and GPS + Cellular versions, stainless steel/titanium cases and the Nike and Hermès editions are separate.

Specification	Apple Watch Series 9 (45 mm, GPS, aluminium)	Apple Watch Series 6 (40 mm, GPS)
Release year	2023	2020
Display	Always-On Retina LTPO OLED; up to 2000 nits, as low as 1 nit; 326 ppi LTPO is a panel technology that can lower the refresh rate dramatically, letting the display stay dimly on when the wrist is down. The 1-nit minimum avoids glare in a dark room. Apple	Always-On Retina LTPO OLED; 324 × 394 pixels, 759 mm² display area; 1000 nits The Always-On display keeps the time and complications visible with the wrist down. Apple
Chip	S9 SiP; 64-bit dual-core processor, 4-core Neural Engine Apple	S6 SiP with 64-bit dual-core processor; W3 wireless chip; U1 Ultra Wideband chip Ultra Wideband availability varies by region. Apple
Storage	64 GB Apple	32 GB Apple
Controls	Digital Crown with haptic feedback, side button, double tap gesture Double tap lets you answer notifications or calls by tapping the thumb and index finger of the watch hand together twice, without touching the screen. Apple	—
Health sensors	Electrical heart sensor, third-generation optical heart sensor, temperature sensing The electrical sensor is for ECG recordings; the optical sensor measures pulse with light. Temperature sensing tracks overnight changes in wrist temperature. Apple	Blood oxygen sensor (Blood Oxygen app), electrical heart sensor (ECG app), third-generation optical heart sensor Apple states Blood Oxygen measurements are not for medical use and are only designed for general fitness and wellness. The ECG app is not intended for people under 22. Apple
Blood Oxygen (US)	On watches sold in the US without the feature, a redesigned version arrives with iOS 18.6.1 and watchOS 11.6.1; the reading is calculated on iPhone The watch collects sensor data, the paired iPhone calculates the value and shows it in the Health app. Watches bought outside the US are not affected. Apple	—
Other sensors	Compass, always-on altimeter, high-g accelerometer, high dynamic range gyroscope, ambient light sensor Apple	—
Location	L1 GPS, GNSS, Galileo and BeiDou It is a single-frequency (L1) receiver; drift in cities can be more likely than with dual-frequency watches. Apple	—
Wireless	Wi-Fi 4 (802.11n), Bluetooth 5.3, second-generation Ultra Wideband Ultra Wideband lets you locate an iPhone 15-family phone with Precision Finding showing direction and distance; availability varies by region. Apple	Wi‑Fi 802.11b/g/n 2.4 and 5 GHz; Bluetooth 5.0 LTE and UMTS are only on GPS + Cellular models. Apple
Battery and charging	Up to 18 hours normal use, up to 36 hours in Low Power Mode; fast charge to about 80% in 45 minutes Fast charging requires Apple’s fast-charging cable and a suitable adapter. Apple	Built-in lithium-ion battery; up to 18 hours; magnetic charging cable (1 m) The 18-hour figure comes from Apple’s August 2020 testing with pre-production watches paired to an iPhone; it varies with use. Apple
Durability	50 m water resistant (ISO 22810:2010); IP6X dust resistant; Ion-X front glass Suitable for swimming. Ion-X is the strengthened glass used on aluminium cases; steel cases use sapphire crystal. Apple	—
Size and weight	45 × 38 × 10.7 mm; 38.7 g; fits 140–245 mm wrists Apple	40 × 34 × 10.7 mm; 30.5 g (aluminium, without band) Apple
Compatibility	iPhone XS or later with iOS 17 or later It cannot be used with Android phones. Apple	Requires an iPhone 6s or later with iOS 14 or later Apple
Case and version	—	40 mm aluminium case, GPS; Silver, Space Gray, Gold, Blue, (PRODUCT)RED Stainless steel and titanium cases were only sold in the GPS + Cellular version. The 44 mm model uses the same chip but has a different display and weight. Apple
Water resistance	—	50 metres (ISO 22810:2010) Suitable for shallow-water swimming in a pool or the sea, but not scuba diving, waterskiing or high-velocity water. Apple
Other sensors and safety	—	Always-on altimeter, compass, accelerometer up to 32 g with fall detection, gyroscope, ambient light sensor; Emergency SOS On the GPS model, Emergency SOS needs the iPhone nearby; otherwise the watch must be on a known Wi‑Fi network with Wi‑Fi Calling on. International emergency calling is only on the cellular model. Apple
Other	—	Speaker, microphone, Apple Pay, GymKit; ceramic and sapphire crystal back Apple