Apple Watch SE (1st generation) vs Apple Watch Ultra 3

Every spec side by side, from each maker's published figures.

Better figure, where one is clearly better

Watch SE (1st generation) compared with Watch Ultra 3
AppleWatch SE (1st generation)AppleWatch Ultra 3
Overview
ReleasedSeptember 2020September 2025
Display
Case sizes40 mm or 44 mm49 mm
PanelLTPO OLEDLTPO OLED
Peak brightness1,000 nits3,000 nits (better)
Always-on displayNoYes
Display detailRetina LTPO OLED; 40mm 324 x 394 pixels and 759 sq mm; 44mm 368 x 448 pixels and 977 sq mmAlways-On Retina display with wide-angle OLEDs and LTPO3; 1Hz refresh; 422 x 514 pixels at 326 ppi; 1,245 sq mm display area; 1 nit minimum brightness; Night Mode for Ultra watch faces
Screen protectionIon-X glassFlat sapphire crystal front
Health and fitness
ECGNoYes
Blood oxygenNoYes
Skin temperatureNoYes
Sleep apnoea alertsNoYes
High blood pressure alertsNoYes
Body compositionNoNo
Fall detectionYesYes
Crash detectionNoYes
GPSSingle-bandDual-band (L1 and L5)
Water resistance50 m100 m (better)
SensorsSecond-generation optical heart sensor; compass, always-on altimeter, accelerometer up to 32 g-forces, gyroscope and ambient light sensorElectrical heart sensor; third-generation optical heart sensor; blood oxygen sensor; temperature sensor; depth gauge to 40 m; water temperature sensor; compass; always-on altimeter (–500 m to 9,000 m); high-g accelerometer; high dynamic range gyroscope; ambient light sensor
Health featuresHigh and low heart rate notifications; Noise app; sleep tracking and automatic handwashing detection in watchOS 7ECG app; Blood Oxygen app; hypertension notifications; sleep apnoea notifications; irregular rhythm notifications; high and low heart rate notifications; Vitals app; sleep stages and sleep score; wrist temperature; Cycle Tracking with retrospective ovulation estimates; Medications; Mindfulness with state of mind tracking; Noise
Fitness featuresGPS, GLONASS, Galileo and QZSS; GymKit; Activity rings; elevation and compass information; dance, functional strength and core workouts in watchOS 7Customisable Action button with Precision Start; custom workouts; Training Load and Workout Effort; customisable heart rate zones; VO2 max; Race Route; Pacer; stride length, ground contact time, cadence, power and vertical oscillation; multisport workouts; offline maps with custom route creation; elevation alerts; Backtrack; swimming with water temperature; recreational diving to 40 m with third-party dive computer apps; cycling with power meters; GymKit
Safety featuresFall Detection and Emergency SOS; international emergency calling on cellular versions in supported regionsEmergency SOS and Find My via satellite; Emergency SOS; international emergency calling; Siren; Crash Detection; Fall Detection; Last Emergency Call Availability Waypoint; torch; noise monitoring; Backtrack
Battery and connections
Battery life (maker's claim)Up to 18 hoursUp to 42 hours
In low-power mode–Up to 3 days
Mobile data optionYesYes
Works withiPhoneiPhone
ChipS5S10
Storage32 GB64 GB (better)
Battery life detailBuilt-in rechargeable lithium-ion batteryUp to 42 hours of normal use; up to 72 hours in Low Power Mode
ChargingMagnetic charging cable; retail packaging updated to USB-C in September 2021; USB power adapter sold separatelyFast charging to 80% in about 45 minutes; 15 minutes for up to 12 hours of normal use; 5 minutes for up to 8 hours of sleep tracking
ConnectivityW3 wireless chip; Wi-Fi 802.11b/g/n at 2.4GHz; Bluetooth 5.0; cellular versions add LTE and UMTS; requires iPhone 6s or later with iOS 14 at launch; Family Setup allows a family member without an iPhone to use a cellular watch managed from an organiser's iPhoneGPS + Cellular only (model A3281) with 5G RedCap and LTE; satellite connectivity; Wi-Fi 4 (802.11n) at 2.4GHz and 5GHz; Bluetooth 5.3; second-generation Ultra Wideband chip; NFC for Apple Pay; L1 and L5 precision dual-frequency GPS (GPS, GLONASS, Galileo, QZSS and BeiDou)
Design
Weight (lightest version)30.49 g (better)61.6 g
SoftwarewatchOSwatchOS
Case materialsRecycled aluminium case; ceramic and sapphire crystal back; 50 m water resistance under ISO 22810:2010 for shallow-water swimmingGrade 5 titanium case (100% recycled titanium) with ceramic and sapphire crystal back; water resistant to 100 m (ISO 22810:2010); EN13319 recreational diving to 40 m; IP6X dust resistant; tested to MIL-STD 810H
Size40mm 40 x 34 x 10.7 mm, GPS 30.49 g or cellular 30.68 g; 44mm 44 x 38 x 10.7 mm, GPS 36.20 g or cellular 36.36 g; case weights exclude bands49 x 44 x 12 mm; 61.6 g (natural) or 61.8 g (black)
BandsCompatible with Apple Watch bands including Solo Loop and Braided Solo Loop; Nike editions have exclusive bands and facesFits 130–210 mm wrists
ColoursSilver, Space Grey or Gold aluminium; Nike Silver or Space GreyNatural or Black titanium
In the boxWatch, band or loop and 1 m magnetic charging cable; no USB power adapter; later packaging supplies a USB-C cableApple Watch Ultra 3, strap, Apple Watch Magnetic Fast Charger to USB-C Cable (1 m)

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