Apple Watch Ultra 4 vs Garmin Fenix 9: which outdoor watch should you buy

The Apple Watch Ultra 4 and the Garmin Fenix 9 are the flagship outdoor watches from Apple and Garmin, and the biggest differences are price, battery and phone support. As of Oct. 25, 2026, the Ultra 4 starts at $799 and needs an iPhone. Garmin's Aug. 25 release lists the Fenix 9 from $999.99 and the titanium Fenix 9 Pro from $1,099.99. Apple rates the Ultra 4 for up to 50 hours of everyday use. Garmin rates the largest Fenix 9 for up to 29 days in smartwatch mode.

Apple announced the Ultra 4 on Sept. 9, 2026, and it went on sale Sept. 18. Garmin announced the Fenix 9 and Fenix 9 Pro on Aug. 25 and said both were available that day. Garmin writes the name fēnix. This comparison is based on Apple's specifications and our Apple Watch guide, and on Garmin's August release and fēnix 9 manual. We haven't tested either watch.

Garmin sells other watch lines. We didn't check its current Forerunner or Epix models for this guide, so the comparison covers the Fenix 9 family, which Garmin's release calls its flagship performance smartwatch lineup.

Ultra 4 vs Fenix 9 at a glance

Apple's battery figures come from its specification page. Garmin's smartwatch-mode figures are in its release, and the activity-mode and Max Battery figures are from its manual, which lists them by mode and size. Garmin rates the 51 mm Fenix 9 Pro Solar for up to 57 days in smartwatch mode with solar charging, assuming three hours a day outside in strong light.

Battery: hours against days

Garmin's smartwatch-mode ratings run to days: up to 10 days on the 43 mm Fenix 9, 16 on the 47 mm and 29 on the 51 mm. The Ultra 4's rating is up to 50 hours, or 84 in Low Power Mode. Apple says 15 minutes of charging adds up to 18 hours of normal use and about 45 minutes reaches 80%. The Garmin sources we read give no charging times.

GPS workouts narrow the gap. Apple rates the Ultra 4 at up to 18 hours of workout tracking, 25 in Extended Workout and 45 in Max Extended Workout, which Apple says is typically enough for a 100-mile race. Garmin's manual lists activity mode at up to 18 hours on the 43 mm, 30 on the 47 mm and 54 on the 51 mm, and up to 49, 81 and 145 hours in Max Battery mode. Even the smallest Fenix 9's Max Battery rating beats the Ultra 4's 45 hours. Both companies rate these as separate modes with different settings, so the figures aren't like-for-like.

GPS, maps and hiking

Apple lists precision dual-frequency GPS for the Ultra 4. For hiking, its spec sheet lists a compass with bearing, incline, elevation and coordinates, custom waypoints, Backtrack, elevation alerts and offline maps with custom route creation. It also lists topographic maps for thousands of national and regional parks and hundreds of curated hikes across all 63 US national parks, both US only.

Garmin's release describes built-in routable maps with a newer map engine, 50% more RAM than the Fenix 8 and panning it says is up to 30% faster, plus a perspective view that shows more detail ahead. With 64GB of memory, Garmin says the Fenix 9 stores twice as many maps as the Fenix 8 and up to 7,000 songs. Its release doesn't describe the GPS chip. It adds a free Garmin Epic feature that groups activities from several days or weeks into one story in Garmin Connect, and stamina zones and a stamina curve that show how endurance changes over time.

If you hike mostly in US parks and carry an iPhone, the Ultra 4's park maps and curated hikes are made for that. If you're out for days without a charger, Garmin's battery ratings matter more.

Satellite, LTE and emergency features

The Ultra 4 has cellular and, by satellite, Emergency SOS, Messages and Find My, plus a siren, Fall Detection and Crash Detection. On Garmin's side, the release says built-in satellite and LTE for voice, text and SOS come with Fenix 9 Pro models, on select versions in all three sizes, and it lists neither for the standard Fenix 9. An active plan is required, LTE coverage isn't available in all regions, and Garmin says satellite and SOS on this watch have "important limitations compared to other inReach devices." The Garmin sources we read give no inReach plan price.

Dive, water and health features

Apple rates the Ultra 4 for 100 meters of water resistance and EN13319 recreational scuba to 40 meters, with a depth gauge, a water temperature sensor, and a dive computer app from the App Store. Garmin says the Fenix 9 is dive-rated up to 40 meters and doesn't list dive features in its release, so compare Garmin's dive tools before buying for diving.

On health, Apple lists an ECG app, a Blood Oxygen app, hypertension and sleep apnea notifications, and, new this year, a Readiness score from its Health Sensing System, as our Apple Watch guide covers. Garmin's release points to garmin.com for its health and wellness features, which we couldn't read.

Subscriptions, apps and phones

Apple Watch needs no subscription, though Apple Fitness+ is optional. Garmin Connect+ is optional too. Garmin said at launch that all existing Garmin Connect features and data remain free, priced Connect+ at $6.99 a month or $69.99 a year with a 30-day trial, and listed AI-powered insights, performance dashboards and expanded LiveTrack among its features. That is the price in Garmin's March 2025 release, so check Garmin's site for today's.

Ultra 4 works only with iPhone: Apple lists an iPhone 11 or later with iOS 27. Garmin's watches pair with the Garmin Connect app, which Garmin publishes on both Apple's App Store and Google Play.

If you're also weighing Meta's Oakley glasses, Garmin's live features with them (voice stats, a status LED and autocapture) need a compatible Garmin device and work only in the US for now. Meta's app also lists Apple Health as a connection for workout summaries. Our Oakley Meta with Garmin and Strava guide has the details.

Garmin or Apple Watch Ultra: how to choose

This advice rests on specifications, not testing.

• Buy the Ultra 4 if you own an iPhone and want one watch for daily wear, workouts, cellular calls and satellite SOS at $799.
• Buy a Fenix 9 if you use Android, or if battery life on long trips matters most. It costs about $200 more than the Ultra 4, and the Pro about $300 more.
• Choose the Fenix 9 Pro if you want satellite and LTE messaging and are willing to pay for an inReach plan.
• If you use Android and aren't set on Garmin, our Galaxy Watch guide and Pixel Watch guide cover the main Android alternatives.