Apple revealed its latest Apple Watch models at its September 9 event alongside the iPhone 18 Pro and iPhone Duo. The Series 12 starts at $399, while the Apple Watch Ultra 4 starts at $799. Both use Apple’s new S11 chip, use the new health detection system and introduce a new readiness score, just like the Whoop and Oura trackers. Beyond that, you’d be hard-pressed to spot many changes from last year’s Apple Watch Series 11 and Ultra 3. The two new smartwatches will go on sale on September 18 after pre-orders open on September 9.
Almost everything Apple presented in its keynote (via YouTube) applies to both watches. Heart rate detection, readiness, Live Rewind, the redesigned Health app and Siri AI on the wrist. The $400 between them buys battery life, titanium, satellite communications, and a pair of training modes designed for events that last more than a day. So if you’re looking to buy one of the new models, here’s what sets them apart and who should actually pay the difference.
Apple Watch Series 12 vs Ultra 4: Which is the same?
Both watches run on the new S11 processor, which Apple calls its most powerful wearable chip, and it’s the first significant upgrade to the Apple Watch chip in years. At the same time, both benefit from Apple’s new health detection system that powers almost all of the new fitness features. These new fitness features are also powered by new optical and electrical heart sensors, which enable heart rate readings every five seconds rather than just during workouts, and HRV measurement every five minutes, 24 times more frequently than before. Apple claims the most accurate heart rate detection in a wearable device out of two, based on a study of more than 1,000 participants compared to competing devices.
Apple’s new Readiness Score also appears on both smartwatches, taking into account recent activity, training load, vital signs and sleep score and returns a score from 0 to 10 each day with one of four recommendations: Recover, Pace Yourself, Ready or Go. The scoring algorithm also comes from Apple’s Heart and Movement Study. Both also claim the most accurate step tracking of any smartwatch, and both get the new Steps complication so you can easily track them.
Audio Intelligence is a brand new feature set that’s also coming to both watches. Live Rewind displays the last 15 seconds of a conversation as text after a double press of the Digital Crown, Siri Recap summarizes conversations afterward, and Sound Recognition signals sirens, alarms, and doorbells. Live Rewind and Siri Recap will arrive in beta later this year, but will require the new watches. Siri AI is coming to the Series 11 and Ultra with the watchOS 27 software update (which will roll out to most other Apple Watches), as is the redesigned Health app with its Longevity tab, Health Age reading, and home movement ratings.
Apple Watch Series 12 vs Ultra 4: What’s the difference?
Most of the differences between the two watches are similar to previous years, with battery life being the biggest difference. The Series 12 offers the same 24 hours of daily use as the Series 11, with 10 hours of outdoor workout tracking and a 15-minute charge that returns 12 hours. The Ultra 4 will last up to 50 hours of daily use – 84 hours in low power mode – and gain 18 hours of battery life from the same 15-minute charge. The Ultra 4 has two new workout tracking modes: Extended Workout, which tracks activities with full GPS and heart rate for 25 hours, and Max Extended Workout, which spans runs, walks and hikes for up to 45 hours while taking a GPS reading every second. The Ultra 4 also claims the most accurate built-in GPS in a sports watch, a claim Apple doesn’t make for the 12 series.
The satellite remains a functionality limited to the Ultra. Emergency SOS, Find My and Satellite Messages without iPhone have arrived on the Ultra 3 and are returning this year. There are no new satellite features on the Ultra 4, so you don’t need to upgrade from last year’s model for connectivity reasons. Satellite connectivity is still free for two years from activation through Globalstar, even though Apple has been saying this for years and never started charging users.
Another big difference between the watches is the physical body and design. The 12 Series is available in 42mm and 46mm sizes, in aluminum, titanium and, for the first time since 2020, pearl white and midnight blue ceramic. The aluminum models feature Apple’s Ceramic Shield 2 display, which is said to be 60% stronger than the Series 11’s Ion-X glass. The Ultra 4 comes in a single material but with two color options (natural titanium or black), a larger body and a brighter display. The suspenders are made in different sizes, but you can use them interchangeably, even if they don’t fit perfectly.
Which of the new Apple Watches should you buy?
You should buy the Ultra 4 if your smartwatch regularly needs to survive more than a day and night without a charger. 50 hours of daily use versus 24 hours is something you will notice on a daily basis. Ultramarathoners and multi-day hikers will benefit from longer battery life, the new Max Extended Workout mode and satellite messaging. Since there’s no way to get these features on older models, you’ll have to buy the Ultra 4, unless you only want satellite messaging, which is available on the Ultra 3.
Everyone should look to the more affordable 12 Series. It comes with the same new processor, updated health sensors, readiness score, and audio intelligence features, which cover almost everything Apple announced for the new watches. A 24-hour battery life should get you through a day and night’s sleep, provided you charge the watch while you shower.
The ceramic casing is a finish rather than a feature, but comes with a higher price tag. Who should spend the extra $400? Those training for long events or working outdoors is where the longer battery life and satellite connectivity comes in handy. Otherwise, buy the Series 12 and keep the difference, as most of the new features are available on both watches.
