Apple Watch Series 12 vs Watch SE 3 specs comparison
Apple Watch Series 12 is the better choice if you want Apple’s full smartwatch experience, with the more advanced display, broader health tracking and more premium hardware. Apple Watch SE 3 covers the essentials for much less, including everyday fitness, notifications, apps and safety features. For most first-time Apple Watch buyers on a budget, SE 3 makes more sense; Series 12 is worth paying extra for if health features and the better screen matter to you.
Full comparison
The full record
77 specifications across 6 areas, with 27 genuine differences.
1. Design & display Mixed
Fact
Apple Watch Series 12
Apple Watch SE 3
Release date
2026-09-18
2025-09-19
Physical size
Aluminum/titanium: 46 x 40 x 9.7 mm or 42 x 37 x 9.7 mm; ceramic: 47 x 41 x 9.85 mm or 43 x 37 x 9.85 mm
44 x 38 x 10.7 mm; 40 x 34 x 10.7 mm
Weight
46 mm: 39.5 g (aluminum GPS), 38.6 g (aluminum GPS + Cellular), 44.9 g (titanium), 51.3 g (Pearl White ceramic), 52.9 g (Night Blue ceramic); 42 mm: 32.2 g, 31.5 g, 36.5 g, 41.7 g and 42.8 g respectively
44 mm: 32.9 g (GPS), 33.0 g (GPS + Cellular); 40 mm: 26.3 g (GPS), 26.4 g (GPS + Cellular)
Material
Aluminum, titanium or ceramic case, 60% tougher than Series 11
Aluminum case
Water resistance
5 ATM; IP6X; depth gauge to 6 m
5 ATM; ISO 22810:2010
Color options
Aluminum: Dark Bronze, Light Gold, Black, Space Gray; Titanium: Radiant Gold, Natural; Ceramic: Pearl White, Night Blue
Starlight, Midnight
Display type
Always-On Retina LTPO3 wide-angle OLED
Always-On Retina LTPO OLED
Display size
42 mm or 46 mm case (ceramic cases are 43 mm or 47 mm tall)
40 mm or 44 mm case
Display resolution
42 mm: 374 x 446 pixels; 46 mm: 416 x 496 pixels
40 mm: 324 x 394 pixels; 44 mm: 368 x 448 pixels
Display brightness
Up to 2,000 nits
Up to 1,000 nits
Display protection
Ceramic Shield 2 on aluminum cases; sapphire front crystal on titanium and ceramic cases
Tough Ion-X front glass; 4x more crack resistant than Apple Watch SE 2
2. Battery & charging Apple Watch Series 12
Fact
Apple Watch Series 12
Apple Watch SE 3
Battery
Rechargeable lithium-ion battery
Rechargeable lithium-ion battery
Battery life
Up to 24 hours; up to 38 hours in Low Power Mode
Up to 18 hours; up to 32 hours in Low Power Mode
Charging
USB-C magnetic fast charging
USB-C magnetic fast charging; up to 80% in about 45 minutes
3. Sensors & positioning Apple Watch Series 12
Fact
Apple Watch Series 12
Apple Watch SE 3
GNSS type
Built-in GNSS
Built-in GNSS
GPS
Yes
Yes
GALILEO
Yes
Yes
GLONASS
Yes
Yes
QZSS
Yes
Yes
Beidou
Yes
Yes
Accelerometer
Yes
Yes
Gyroscope
Yes
Yes
Barometric altimeter
Yes
Yes
Compass
Yes
Yes
Ambient light sensor
Yes
Yes
Optical heart rate
Yes (always-on optical heart sensor; high-frequency background tracking)
Yes
Electrical heart rate
Yes
No
SpO2
Yes
No
Temperature
Yes
Yes
Galvanic skin response
No
No
Microphone
Yes
Yes
Speakers
Yes
Yes
Vibration motor
Yes
Yes
4. Health & activity Apple Watch Series 12
Fact
Apple Watch Series 12
Apple Watch SE 3
Steps
Yes
Yes
Distance
Yes
Yes
Calories burned
Yes
Yes
Floors
Yes
Yes
Sports tracking
Yes
Yes
Sleep
Yes
Yes
Heart rate
Yes
Yes
HRV
Yes (Up to 24x more frequent than Series 11)
Yes
Stress
No
No
Blood oxygen
Yes
No
Respiration rate
Yes
Yes
Skin temperature
Yes
Yes
ECG
Yes
No
Blood pressure
Hypertension notifications (no direct blood-pressure measurement)
No
Body composition
No
No
Glucose
No
No
Hydration level
No
No
UV exposure
No
No
Calorie intake
No
No
Hyperglycemia risk assessment
No
No
Arterial stiffness detection
No
No
Pulse wave arrhythmia analysis
Yes
Yes
5. Smart features No clear edge
Fact
Apple Watch Series 12
Apple Watch SE 3
Smartphone compatibility
iPhone 11 or later or iPhone SE (2nd generation or later) with iOS 27 or later
iPhone 11 or later with iOS 26 or later
Operating system at launch
watchOS 27
watchOS
Processor
Apple S11, 64-bit dual-core processor; 4-core Neural Engine; Audio Intelligence
Apple S10, 64-bit dual-core; 4-core Neural Engine
Storage
64 GB
64 GB
Bluetooth
Yes (5.3)
Yes (5.3)
Wi-Fi
Yes (Wi-Fi 4 / 802.11n, 2.4/5 GHz)
Yes (Wi-Fi 4 / 802.11n, 2.4 GHz)
NFC / connected pay
Yes (Apple Pay)
Yes (Apple Pay)
UWB
Yes (2nd-generation UWB)
No
Cellular
Optional (5G RedCap and LTE on supported regional models)
Optional (5G RedCap and LTE on supported regional models)
Smartphone notifications
Yes
Yes
Bluetooth calling
Yes (standalone on cellular models; via paired iPhone otherwise)
Yes (standalone on cellular models; via paired iPhone otherwise)
Smartphone music control
Yes
Yes
On-board music storage
Yes
Yes
Voice assistant
Siri AI powered by Apple Intelligence
Siri
6. Navigation & safety No clear edge
Fact
Apple Watch Series 12
Apple Watch SE 3
Maps
Yes
Yes (Apple Maps)
Offline maps
Yes
Yes (synced from iPhone)
Navigation
Yes
Yes (Apple Maps turn-by-turn)
Emergency SOS
Yes
Yes
Satellite SOS
No
No
Fall detection
Yes
Yes
LED flashlight
No
No
Diving
No
No