Compare Apple Watch models

Series 12 and Ultra 4 share Apple’s new Health Sensing System. Compare them with Series 11, Ultra 3 and SE 3 on sensors, battery and outdoor features.

Specs checked September 14, 2026. Figures are Apple’s published specifications and claims, not hands-on tests. We don’t list prices.

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Apple Watch Series 12 vs Apple Watch Ultra 4 vs Apple Watch Series 11
Spec	Apple Watch Series 12	Apple Watch Ultra 4	Apple Watch Series 11
Health sensing
Heart sensors	Health Sensing System (Redesigned optical and electrical heart sensors)	Health Sensing System (Redesigned optical and electrical heart sensors)	Third-generation optical heart sensor (Plus electrical heart sensor)
Background heart rate	Every 5 seconds (Apple: 60× more often than Series 11)	Every 5 seconds (Same as Series 12)	Not listed
Readiness score	Readiness score	Readiness score	Not available
ECG app	Supported	Supported	Supported
Blood Oxygen	Supported	Supported	Supported
Hypertension notifications	Supported	Supported	Supported
Sleep	Sleep score (Plus sleep apnea notifications)	Sleep score (Plus sleep apnea notifications)	Sleep score (Plus sleep apnea notifications)
Chip and battery
Chip	S11	S11	S10
Battery life	24 h (Normal use), 38 h (Low Power Mode)	50 h (Normal use), 84 h (Low Power Mode)	24 h (Normal use), 38 h (Low Power Mode)
Fast charge	15 min adds up to 12 h (80% in about 30 min)	15 min adds up to 18 h (80% in about 45 min)	15 min adds up to 8 h (80% in about 30 min)
Coming later in 2026	Audio Intelligence (Apple: arrives later this year, needs S11)	Audio Intelligence (Apple: arrives later this year, needs S11)	Not listed
Design and display
Case	42 or 46 mm (Aluminum, titanium or ceramic)	49 mm (Titanium)	42 or 46 mm (Aluminum or titanium)
Front crystal	Ceramic Shield 2 on aluminum (Sapphire on titanium and ceramic)	Flat sapphire crystal	Ion-X glass on aluminum (Sapphire on titanium)
Peak brightness	Up to 2000 nits	Up to 3000 nits	Up to 2000 nits
Outdoors and connectivity
Water and dust	WR50 (IP6X dust)	WR100 (IP6X dust)	WR50 (IP6X dust)
GPS	Precision L1 GPS	Precision dual-frequency GPS (L1 and L5)	L1 GPS
Satellite communications	Not available	Supported (Coverage and plan limits apply)	Not available
Cellular	Optional 5G	5G built in	Optional 5G
Depth gauge	Built in	Built in	Built in
Availability	September 18 (Pre-orders opened Sep 9, 2026)	September 18 (Pre-orders opened Sep 9, 2026)	Launched Sep 2025

Quick pick

Choose Series 12 if you want the 2026 health default: background heart rate every 5 seconds and a daily readiness score.
Choose Ultra 4 if battery life, dual-frequency GPS, satellite or the 49 mm titanium case is the real need. The health sensors match Series 12.
Series 11 Keep it if a readiness score and faster heart-rate sampling weren’t the gap. ECG, sleep score and sleep apnea notifications already work.

Where to buy

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Every Apple Watch model on this page

Apple Watch Series 12: All-new Health Sensing System and a daily readiness score.
Apple Watch Ultra 4: Same health sensors, built for endurance, GPS and satellite.
Apple Watch Series 11: ECG, sleep score and sleep apnea notifications already here.
Apple Watch Ultra 3: Ultra battery, dual-frequency GPS and satellite on S10.
Apple Watch SE 3: Sleep score and temperature sensing, without ECG or Blood Oxygen.