Xiaomi Watch S4 vs Apple Watch Ultra 2

Xiaomi Watch S4

Xiaomi Watch S4

vsApple Watch Ultra 2

Apple Watch Ultra 2

Xiaomi Watch S4Apple Watch Ultra 2
Display1.32" AMOLED, 466 x 466 pixels, 352 ppi, 60Hz, up to 1500 nits (HBM)Flat crystal, up to 3000 nits
Size41 mm; 41.2 x 41.2 x 9.5 mm, approx. 32 g without strap—
CaseStainless steel frame—
BatteryUp to 8 days (light use), up to 4 days (normal use), up to 3 days (heavy use), 320 mAh, magnetic 2-pin charging dockUp to 36 hours; up to about 60 hours in low-power mode
Water Resistance5 ATMWR100 / EN13319, recreational dives to 40 m
PositioningBuilt-in dual-frequency L1+L5 GNSS: GPS, Galileo, GLONASS, BeiDou, QZSS—
ConnectivityBluetooth 5.4, Bluetooth calling, NFC (varies by region)Cellular, dual-frequency GPS (L1 + L5)
SensorsHeart rate with blood oxygen, accelerometer, gyroscope, ambient light, compass, barometer, skin temperature—
Sports Modes150+ sports modes—
OSXiaomi HyperOS 3watchOS 10 (at launch)
CompatibilityAndroid 8.0 or later, iOS 14.0 or later—
StrapFluororubber (black, mint green), leather (white), Milanese (Sunset gold), 120-190 mm adjustable—
ColorsBlack, White, Sunset gold, Mint green—
Case Size—49mm titanium
Chipset—Apple S9 SiP, 2nd-gen Ultra Wideband
Health Sensors—Heart rate, water temperature, sleep apnea detection, blood oxygen (calculated on paired iPhone)