Apple Watch Ultra 4 vs Apple Watch Ultra 2

Ultra 2 reached stores on 22 September 2023 and Ultra 4 on 18 September 2026, both at $799. In those three years Apple left the case alone, still 49 by 44 by 12mm in natural or black titanium with a flat sapphire front, and Ultra 4 weighs less than 2 grams more. Nearly everything inside changed.

Ultra 4 and Ultra 2 side by side

Spec	Apple Watch Ultra 4	Apple Watch Ultra 2
Announced	9 September 2026	12 September 2023
Case	49 × 44 × 12mm Grade 5 titanium	Same
Weight	63.0 g natural; 63.1 g black	61.4 g natural; 61.8 g black
Display	LTPO3, 422 × 514, 1,245 sq mm	LTPO2, 410 × 502, 1,185 sq mm
Peak brightness	3,000 nits	3,000 nits
Always On	Updates once a second (1Hz)	About once a minute
Chip / storage	S11; 64GB	S9; 64GB
Normal use	Up to 50 hours	Up to 36 hours
Low Power Mode	Up to 84 hours	Up to 72 hours
GPS workouts	18 hours; 25 Extended; 45 Max Extended	Not published
Charging	About 80% in 45 minutes	About 80% in 1 hour
Cellular	5G and LTE (model A3579)	LTE and UMTS
Satellite	SOS, Messages, Find My	No
Siren range	Up to 600 feet (180 m)	Not published
Heart sensors	Health Sensing System	Third-generation optical + electrical
Gestures	Single tap, double tap, wrist flick	Double tap
iPhone needed	iPhone 11 or later, iOS 27	iPhone Xs or later, iOS 18
US launch price	$799	$799

Satellite is the safety upgrade

If you hike, sail or drive where phones lose signal, this settles it. Ultra 4 can send Emergency SOS, Messages and Find My over satellite. Ultra 2 can’t use satellite at all.

The rest of the safety kit is closer. Both have a siren, dual speakers and a three-microphone array. Hold Ultra 4’s Action Button and Apple says the siren carries up to 600 feet, about 180 meters; Ultra 4 can also put its flashlight on that button.

Battery and charging

Apple rates Ultra 2 for up to 36 hours, on a test day of time checks, notifications, a 60-minute workout with music and some LTE use. Ultra 4 is rated for 50 hours, the longest Apple has given any Apple Watch, and 84 in Low Power Mode against 72.

Ultra 4 also gets GPS workout ratings: 18 hours for an outdoor workout, 25 in Extended Workout and 45 in Max Extended Workout. That last mode covers outdoor running, walking and hiking with GPS checking your position every second, and Apple’s example is a 100-mile race. It isn’t a figure for swimming, cycling or diving.

Charging is quicker too. Ultra 4 reaches about 80% in 45 minutes, against about an hour for Ultra 2. Fifteen minutes on the charger buys about 18 hours of normal use, and five minutes about 10 hours of sleep tracking. Both come with the magnetic fast charger to USB-C and one band.

Same brightness, a faster Always On

Both screens peak at 3,000 nits, dim to 1 nit and sit under flat sapphire at 326 pixels per inch. Ultra 4’s LTPO3 panel, with wide-angle OLEDs, is a little bigger: 422 × 514 pixels over 1,245 square millimeters, against 410 × 502 and 1,185 on Ultra 2’s LTPO2.

The change you’ll notice is Always On. Ultra 4 refreshes the dimmed face once a second (1Hz), so a seconds hand keeps moving with your wrist down. Ultra 2 updates it about once a minute; Apple made the switch with Ultra 3. Both have Night Mode for the Modular Ultra and Wayfinder faces, and Ultra 4 adds it to Orienteering.

New heart sensors and a readiness score

Ultra 2 already covers the health basics. It has a third-generation optical heart sensor and an electrical sensor for the ECG app (ages 22 and up, where available), Blood Oxygen as a wellness feature, a temperature sensor, sleep stages, and sleep apnea notifications for ages 18 and up.

Ultra 4’s Health Sensing System is new hardware: redesigned optical and electrical sensors with larger green LEDs. Apple says it checks your heart rate in the background every five seconds, all day, which it calls 60× as often as Ultra 3, and samples HRV as often as every five minutes, 24× as often. That feeds readiness, a 0–10 score each morning labeled Recover, Pace Yourself, Ready or Go For It. It’s built from your activity, training load, vitals and sleep, and it updates through the day. Ultra 4 also gives you a Sleep score.

ECG and Blood Oxygen depend on your region on both watches, and none of these features is a diagnosis.

Chips, radios and your iPhone

S9 brought double tap and on-device Siri to Ultra 2. S11 runs Ultra 4’s Audio Intelligence features, with Live Rewind and Siri Recap due as betas in late 2026, and Ultra 4 adds single tap and wrist flick to double tap. Both have 64GB of storage.

GPS is precision dual-frequency on both: Ultra 4 lists GPS, Galileo, QZSS and BeiDou, and Ultra 2 adds GLONASS. Apple calls Ultra 4’s the most accurate on-device GPS in a sports watch, which is its own claim. Cellular moves from LTE and UMTS on Ultra 2 to 5G and LTE on Ultra 4 (model A3579), with international roaming on both. Wi-Fi 4, Bluetooth 5.3, a second-generation ultra-wideband chip, Apple Pay and GymKit are on both.

Ultra 4 needs an iPhone 11 or later on iOS 27. Ultra 2 works with an iPhone Xs or later on iOS 18 or later.

What Ultra 2 already had

The outdoor kit hasn’t changed. Both have the customizable Action Button, a depth gauge and water-temperature sensor, recreational dives to 40 meters with an App Store dive app that opens automatically at about 1 meter, water resistance to 100 meters, IP6X dust protection and testing to a list of MIL-STD-810H methods. Both work on the wrist from minus 20 to 55 degrees Celsius.

Training tools mostly match. Both track cadence, stride length, ground contact time and vertical oscillation on runs, and Ultra 4 adds running power. Both have the compass, Backtrack, offline maps, U.S. topographic maps and curated hikes across 63 U.S. national parks.

Neither comes smaller. Both are 49mm only and fit wrists from 130 to 210mm, so if you want a 42mm or 46mm everyday watch, an Ultra isn’t it. Hermès Ultra 4 is sold as a separate collection.

Apple’s environmental claims differ: Ultra 4 is made with 45% recycled content, including recycled titanium in the case, while Ultra 2 was carbon neutral when paired with certain loops and has a recycled-content claim of its own.

What they cost

Apple launched Ultra 2 at $799 on 12 September 2023 and Ultra 4 at $799 on 9 September 2026; bands, Hermès, a cellular plan and AppleCare cost extra. Ultra 2 is three years old, so what it costs now is up to the seller; weigh that gap against satellite, the new sensors, 5G and the extra battery. Check Ultra 4’s current price at apple.com before you buy.