Apple Watch Series 8 vs Apple Watch Ultra 2

If you’re choosing between these two, you’re shopping discounted or used: neither is the current model in its line. Series 8 was announced on 7 September 2022 and reached US stores on 16 September 2022; Ultra 2 followed on 12 September 2023, with stores from 22 September 2023. One is an aluminum or stainless everyday watch, the other the second-generation 49mm titanium Ultra.

The specs side by side

Spec	Apple Watch Series 8	Apple Watch Ultra 2
Announced	7 September 2022	12 September 2023
Case	41mm or 45mm aluminum or stainless steel, 10.7mm thick	49mm Grade 5 titanium, 12mm thick
Weight	31.9 g (41mm aluminum GPS); 38.8 g (45mm aluminum GPS)	61.4 g natural; 61.8 g black
Display	352 × 430 or 396 × 484, up to 1,000 nits	410 × 502 at 326 ppi, up to 3,000 nits
Chip and storage	S8; 32GB	S9; 64GB
Normal use	Up to 18 hours	Up to 36 hours
Low Power Mode	Not published	Up to 72 hours
Charge to 80%	Not published	About 1 hour
GPS	L1	L1 and L5 dual-frequency
Water	50m, shallow swimming	100m; recreational scuba to 40m
Action Button, siren, depth gauge	No	Yes
Satellite	No	No
watchOS 27	No	Yes
iPhone needed	iPhone 8 or later, iOS 16 or later	iPhone Xs or later, iOS 18 or later
US launch price	$399	$799

Size and screen

Series 8 measures 41 × 35 × 10.7mm or 45 × 38 × 10.7mm, with 904 or 1,143 square millimeters of display, and peaks at 1,000 nits. Aluminum came in midnight, starlight, silver and (PRODUCT)RED, and stainless steel in graphite, silver and gold. There’s no titanium Series 8, and Apple lists stainless weights only for the cellular models, at 42.3 and 51.5 grams.

Ultra 2 has one size, 49 × 44 × 12mm, in natural or black titanium, for wrists from 130 to 210mm. Its 1,185-square-millimeter Always-On LTPO2 OLED sits under flat sapphire at 326 ppi, peaks at 3,000 nits and dims to 1 nit; at launch in 2023, Apple called it its brightest display yet. Night Mode, which turns the display red, works on the Modular Ultra and Wayfinder faces. Weights are for the case alone, without a band.

Battery and charging

Apple gives Series 8 a single battery figure: up to 18 hours. There’s no Low Power Mode rating, no workout rating and no charging time, just the Magnetic Fast Charger to USB-C in the box.

Ultra 2 is rated for up to 36 hours of normal use, in a test that mixes time checks, notifications, a 60-minute workout with music and some time on LTE, and up to 72 hours in Low Power Mode. It charges to about 80 percent in about an hour. There are no separate GPS workout ratings; Apple started giving those with later Ultras.

Water, GPS and the Ultra hardware

Series 8 is water resistant to 50 meters under ISO 22810:2010, which Apple limits to shallow swimming: no scuba, waterskiing or high-velocity water. It’s IP6X dust-resistant, with no MIL-STD testing. Its safety features are Emergency SOS, international emergency calling on cellular models, Fall Detection and Crash Detection, which runs on a high-g accelerometer rated up to 256 g-forces.

Ultra 2 is built for the water. It’s rated to 100 meters under the same ISO standard, for swimming, recreational scuba to 40 meters and high-speed water sports. It has a depth gauge and a water-temperature sensor, the Depth app opens on its own once you pass 1 meter, and you can add a dive computer app from the App Store, such as Oceanic+, which needs a subscription. It’s IP6X too, and tested against a list of MIL-STD-810H methods: altitude, temperature, immersion, freeze and thaw, ice, shock and vibration. That’s a list of lab tests, not a promise of military toughness.

GPS is the other clear split. Series 8 has L1 GPS with GLONASS, Galileo, QZSS and BeiDou; Ultra 2 has precision dual-frequency GPS on L1 and L5 with the same systems. Both use LTE and UMTS on cellular models, with roaming that depends on your carrier, and neither has 5G.

The Ultra hardware goes beyond the dive gear. Ultra 2 has a customizable Action Button, which also handles Precision Start for workouts, a siren, dual speakers, and three microphones with beamforming and wind-noise reduction. Hiking gets Backtrack, offline maps, US topographic maps and curated hikes in 63 US national parks, where Series 8 offers a compass and an always-on altimeter. Ultra 2 is rated for minus 20 to 55 degrees Celsius on the wrist.

Chips, health and updates

Series 8 runs the S8, a 64-bit dual-core chip, with the W3 wireless chip, the first-generation U1 ultra-wideband chip and 32GB of storage. Ultra 2 runs the S9, also dual-core, with a 4-core Neural Engine and 64GB, and adds double tap and on-device Siri.

Both use a third-generation optical heart sensor and an electrical heart sensor, both have the Blood Oxygen app (a wellness feature, not a medical device) and both have the ECG app for people 22 and older where Apple offers it. Neither has the Health Sensing System; that came with the 2026 watches.

Series 8 brought wrist temperature sensing at its 7 September 2022 launch, with two sensors and retrospective ovulation estimates. Ultra 2 has a temperature sensor, not for medical use, plus its water-temperature sensor. Series 8 got sleep stages through watchOS 9 software; Ultra 2 has the Sleep app with stages, plus sleep apnea notifications for people 18 and older, available on Ultra 2 and Series 9 or later where Apple offers them. Those notifications are not a diagnosis.

Workouts follow the same pattern. Series 8 got Apple’s enhanced Workout app with watchOS 9. Ultra 2 lists dedicated running, hiking, cycling, swimming and diving features, plus skiing, rowing, golf and more.

Software support is the long-term difference. Series 8 launched on watchOS 9 and doesn’t get watchOS 27; Ultra 2 launched on watchOS 10 and does. Apple hasn’t said when Ultra 2’s updates will end.

Phones, bands and price

Series 8 pairs with an iPhone 8 or later on iOS 16 or later. Ultra 2 asks for an iPhone Xs or later, including iPhone SE (2nd generation or later), running iOS 18 or later. Newer watchOS versions can ask for a newer iOS than either watch launched with, so make sure your iPhone still qualifies.

Each comes with one band and a Magnetic Fast Charger to USB-C cable, and both have Apple Pay and GymKit. Series 8 takes standard Apple Watch bands; Ultra 2 uses the Ultra fitting, with the Trail, Alpine and Ocean bands, not a 22mm quick-release lug.

Series 8 started at $399 for aluminum, with stainless and cellular models costing more. Ultra 2 started at $799. Both are launch prices, and older watches sell for whatever the seller asks, so compare the current price before you buy.