Apple Watch SE 3 vs Apple Watch Series 3

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Watch SE 3 compared with Watch Series 3

	AppleWatch SE 3	AppleWatch Series 3
Overview
Released
Released	September 2025	September 2017
Display
Case sizes
Case sizes	40 mm or 44 mm	38 mm or 42 mm
Panel
Panel	LTPO OLED	OLED
Peak brightness
Peak brightness	1,000 nits	1,000 nits
Always-on display
Always-on display	Yes	No
Display detail
Display detail	Always-On Retina display with OLED and LTPO; 324 x 394 pixels (40mm) or 368 x 448 pixels (44mm) at 326 ppi; 759 or 977 sq mm display area; 2 nits minimum brightness	Retina OLED with Force Touch; 38mm 272 x 340 pixels and 563 sq mm; 42mm 312 x 390 pixels and 740 sq mm; wake by wrist raise or tap (Wareable)
Screen protection
Screen protection	Ion-X front glass, 4x more crack resistant than SE 2	Ion-X glass on aluminium; sapphire crystal on stainless steel and ceramic (PhoneArena)
Health and fitness
ECG
ECG	No	No
Blood oxygen
Blood oxygen	No	No
Skin temperature
Skin temperature	Yes	No
Sleep apnoea alerts
Sleep apnoea alerts	Yes	No
High blood pressure alerts
High blood pressure alerts	No	No
Body composition
Body composition	No	No
Fall detection
Fall detection	Yes	No
Crash detection
Crash detection	Yes	No
GPS
GPS	Single-band	Single-band
Water resistance
Water resistance	50 m	50 m
Sensors
Sensors	Second-generation optical heart sensor; temperature sensor; compass; always-on altimeter; high-g accelerometer; high dynamic range gyroscope; ambient light sensor	Optical heart sensor, barometric altimeter, accelerometer up to 16 g-forces, gyroscope and ambient light sensor
Health features
Health features	Heart Rate app; high and low heart rate notifications; irregular rhythm notifications; sleep apnoea notifications; sleep stages and sleep score; Vitals app (heart rate, respiratory rate, wrist temperature and sleep duration); Cycle Tracking with fertile window and retrospective ovulation estimates, perimenopause and menopause support; Medications; Mindfulness; Noise	Heart-rate monitoring including resting and recovery measurements; alerts for elevated heart rate while inactive in watchOS 4
Fitness features
Fitness features	Custom workouts; Training Load; customisable heart rate zones; VO2 max; Race Route; Pacer; cadence, stride length, ground contact time, vertical oscillation and running power; automatic track detection; multisport workouts; offline maps with custom route creation; Backtrack; pool and open-water swimming with SWOLF; cycling power zones with Bluetooth accessories; GymKit	GPS, GLONASS, Galileo and QZSS; elevation gain and flights climbed; pool and open-water swimming, HIIT workouts and GymKit
Safety features
Safety features	Emergency SOS; international emergency calling; Fall Detection; Crash Detection; Check In; Backtrack; noise monitoring	Emergency SOS
Battery and connections
Battery life (maker's claim)
Battery life (maker's claim)	Up to 18 hours	Up to 18 hours
In low-power mode
In low-power mode	Up to 32 hours	–
Mobile data option
Mobile data option	Yes	Yes
Works with
Works with	iPhone	iPhone
Chip
Chip	S10	S3
Storage
Storage	64 GB (better)	8 GB
Battery life detail
Battery life detail	Up to 18 hours of normal use; up to 32 hours in Low Power Mode; up to 7 hours of outdoor workout	Built-in rechargeable lithium-ion battery; cellular performance depends on coverage and usage
Charging
Charging	Fast charging to 80% in about 45 minutes; 15 minutes for up to 8 hours of normal use; 8 minutes for up to 8 hours of sleep tracking	USB-A magnetic charging cable; Apple lists a USB power adapter for the cellular model only
Connectivity
Connectivity	Wi-Fi 4 (802.11n) at 2.4GHz; Bluetooth 5.3; NFC for Apple Pay; L1 GPS (GLONASS, Galileo, QZSS and BeiDou); GPS + Cellular models (A3326, A3328) with 5G RedCap and LTE	W2 wireless chip; Wi-Fi 802.11b/g/n at 2.4GHz; Bluetooth 4.2; cellular versions add LTE, UMTS and eSIM with a compatible carrier plan. At launch GPS required iPhone 5s and cellular iPhone 6, both with iOS 11; updated Apple support requires iPhone 6s
Storage
Storage	–	8 GB on GPS models; 16 GB on GPS + Cellular models
Design
Weight (lightest version)
Weight (lightest version)	26.3 g (better)	26.7 g
Software
Software	watchOS	watchOS
Case materials
Case materials	100% recycled aluminium case with nylon composite and sapphire crystal back; water resistant to 50 m (ISO 22810:2010)	Aluminium GPS models have a composite back; cellular models have ceramic and sapphire crystal back; steel and ceramic cases sold with cellular only; water resistance under ISO 22810:2010 for shallow-water swimming
Size
Size	40mm is 40 x 34 x 10.7 mm, 26.3 g (GPS) or 26.4 g (GPS + Cellular); 44mm is 44 x 38 x 10.7 mm, 32.9 g (GPS) or 33.0 g (GPS + Cellular)	Aluminium 38mm 38.6 x 33.3 x 11.4 mm, GPS 26.7 g or cellular 28.7 g; 42mm 42.5 x 36.4 x 11.4 mm, GPS 32.3 g or cellular 34.9 g. Steel uses the same dimensions at 42.4 g and 52.8 g. White ceramic 38mm 39.2 x 34.0 x 11.8 mm, 40.1 g; 42mm 42.6 x 36.5 x 11.4 mm, 46.4 g. Weights exclude bands
Bands
Bands	Fits 130–200 mm wrists (40mm) or 140–245 mm wrists (44mm)	Sport Band or Sport Loop on aluminium; Sport Band or Milanese Loop on steel; Nike Sport Band or Nike Sport Loop on Nike+; leather and additional Sport Band on Hermès; Sport Band on Edition. Nike+ reached limited availability 5 October 2017
Colours
Colours	Midnight or Starlight aluminium	Silver, Space Grey and Gold aluminium; Silver or Space Black stainless steel; White or Grey ceramic
In the box
In the box	Apple Watch SE 3, strap, Apple Watch Magnetic Fast Charger to USB-C Cable (1 m)	Watch and band, USB-A magnetic charging cable; cellular models include USB power adapter and Hermès includes an additional Sport Band