Apple Watch Ultra 4 vs Garmin fēnix 8

Garmin announced the fēnix 8 on 27 August 2024, two years before Apple’s Ultra 4 arrived on 9 September 2026, and Garmin has since moved on to the fēnix 9. The fēnix 8 also comes in 43mm and 51mm AMOLED sizes and in Solar versions, each with different battery life; the ratings below are for the 47mm AMOLED.

Key specs

Spec	Apple Watch Ultra 4	Garmin fēnix 8 (47mm AMOLED)
Announced	9 September 2026	27 August 2024
Works with	iPhone 11 or later, iOS 27	iPhone or Android (Garmin Connect)
Software	watchOS 27	Garmin’s own
Case	49 × 44 × 12mm Grade 5 titanium	47mm; thickness not published
Weight	63.0 g natural; 63.1 g black	Not published
Display	Always-On LTPO3 OLED, 422 × 514, up to 3,000 nits	AMOLED; resolution and brightness not published
Everyday battery	Up to 50 hours; 84 in Low Power Mode	Up to 16 days with gesture; 7 always-on; 23 battery saver
GPS battery	18 hours; 25 Extended; 45 Max Extended Workout	47 hours GPS-only; 35 multi-band; 81 Max Battery GPS
Satellite	SOS, Messages, Find My	None; no inReach
Cellular	5G RedCap and LTE	None
Water and diving	100m; EN 13319 to 40m	10 ATM; EN 13319 to 40m
Flashlight	Screen flashlight on the Action Button	LED with red light and strobe
US launch price	$799	Series from $999.99

The phone you use comes first

Ultra 4 needs an iPhone 11 or later, including iPhone SE (2nd generation or later), on iOS 27, and there’s no Android setup. Its cellular, satellite and safety features work within Apple’s rules for the paired iPhone, and you get watchOS 27, Apple Pay and GymKit. If your days already run on Apple Pay, iMessage and a cellular plan on your wrist, it fits straight in, but it won’t follow you to Android.

The fēnix 8 pairs with an iPhone or an Android phone through Garmin Connect, which carries notifications, music services, Garmin Messenger and LiveTrack. It runs Garmin’s own software, not Wear OS or watchOS, and Garmin Pay works in the countries and with the banks Garmin supports. If you change phones every few years, it’s the one that won’t make you change watch brands too.

Battery: hours against days

Mode	Apple Watch Ultra 4	Garmin fēnix 8 (47mm AMOLED)
Everyday	Up to 50 hours normal use	Up to 16 days smartwatch with gesture; 7 days always-on
Low power	Up to 84 hours Low Power Mode	Up to 23 days battery saver
GPS	Up to 18 hours outdoor workout; 25 hours Extended Workout	Up to 47 hours GPS-only; 38 all systems; 35 multi-band
GPS, screen always on	No separate rating	Up to 37, 30 and 28 hours
Longest GPS mode	Up to 45 hours Max Extended Workout	Up to 81 hours Max Battery GPS
Multi-day mode	None listed	Up to 17 days Expedition
GPS with music	No rating given	Up to 10 hours
Quick charge	15 minutes for up to 18 hours of normal use	No rating given

The headline numbers measure different things. Fifty hours is Apple’s normal-use day; 16 days is Garmin’s smartwatch mode with the screen waking when you raise your wrist, not 16 days of GPS. With GPS running, the gap is much smaller than it looks: up to 45 hours on Ultra 4 in Max Extended Workout against 47 hours GPS-only on the fēnix 8, which stretches to 81 in Max Battery GPS mode. Apple’s 45 hours covers outdoor running, walking and hiking with GPS checking your position every second; it doesn’t apply to swimming, cycling or diving.

Ultra 4 comes with a Magnetic Fast Charger to USB-C and reaches about 80 percent in 45 minutes, and 5 minutes on it buys up to 10 hours of sleep tracking. Charge the fēnix 8 between 0 and 45 degrees Celsius, Garmin says.

Satellite, cellular and safety

Ultra 4 sends Emergency SOS, Messages and Find My over satellite, and it’s a cellular watch with 5G RedCap and LTE, so it can reach people when your phone isn’t with you. Hold the Action Button and it sounds a siren Apple says carries about 180 meters; the same button can start a workout or the screen flashlight.

The 47mm fēnix 8 has neither radio: no inReach and no cellular. It takes calls through its speaker and microphone while paired, and some voice commands work without the phone nearby, but incident detection, assistance and LiveTrack all need the phone. Garmin Messenger sends two-way texts when both people have the app. What it adds is a dedicated LED flashlight with variable intensity, a red light and a strobe, a different thing from Apple’s screen flashlight.

If you want to text from beyond cell range without a phone, only Ultra 4 does it.

Screen and case

Ultra 4’s Always-On LTPO3 OLED sits under flat sapphire: 422 by 514 pixels at 326 pixels per inch, up to 3,000 nits and down to 1 nit. The Grade 5 titanium case is 49 millimeters tall, 44 wide and 12 thick, weighs 63.0 grams in natural titanium or 63.1 grams in black without a band, and fits wrists from 130 to 210 millimeters. One band comes in the box; this year’s sport bands are the Trail Loop, Alpine Loop and a translucent Ocean Band.

Garmin calls the fēnix 8’s display a bright AMOLED and makes the sapphire lens optional, but it doesn’t give the 47mm model’s brightness, resolution, weight, thickness, processor or storage.

Maps, training and health

Ultra 4 has offline maps, U.S. topographic maps and curated hikes in all 63 U.S. national parks, and its running metrics include power. Apple’s Health Sensing System checks your heart rate in the background every five seconds and feeds a daily readiness score from 0 to 10. Sleep tracking covers stages and a Sleep score, with sleep apnea notifications where Apple offers them, and ECG and Blood Oxygen depend on your region.

On the fēnix 8, TopoActive maps come on sapphire models, other versions download maps, and Outdoor Maps+ is a subscription. Garmin offers an ECG app in some regions, for ages 22 and up, and a wrist-based Pulse Ox reading that isn’t a medical device and isn’t available in every country. Sleep tracking adds nap detection, a morning report and Body Battery, but Garmin lists no skin-temperature sensor.

Diving and durability

Both carry EN 13319 certification for dives to 40 meters, with different tools underwater. Ultra 4’s depth gauge is accurate to about 1 meter, dive apps open automatically at 1 meter, and it has a water-temperature sensor. The fēnix 8 reads depth from 0 to 40 meters at 0.1-meter resolution, works underwater from 0 to 40 degrees Celsius, has scuba and apnea modes, and is the one that names a decompression model, Bühlmann ZHL-16C.

Ultra 4 adds IP6X dust protection and a list of specific MIL-STD-810H tests, and Apple rates it for minus 20 to 55 degrees Celsius on the wrist and altitudes from minus 500 to 9,000 meters.

Price

Ultra 4 starts at $799 in the US; bands, the Hermès edition, a cellular plan and AppleCare cost extra. Garmin’s suggested price for the fēnix 8 range started at $999.99 on 27 August 2024, and sapphire, a titanium bezel and the larger sizes change it, while the Solar models have different batteries altogether. Garmin’s higher launch price pays for days of battery, maps and the freedom to switch phones; Apple’s lower one pays for satellite messaging, cellular and a 3,000-nit screen, as long as you stay on iPhone. Prices move, so check apple.com and garmin.com before you buy.