Apple Watch Series 12 finally gets the upgrade long-time owners have been waiting for. The new model pairs the new, faster chip with a redesigned health sensing system. It also brings Apple Intelligence to your wrist for the first time.
Apple unveiled the Apple Watch Series 12 and the beefier Apple Watch Ultra 4 on Wednesday during its Surprise and Shine event. Both watches arrive alongside a new watchOS 27 update. They share the same faster Apple silicon processor and advanced health sensors, and together mark one of the most notable hardware refreshes the Apple Watch has seen in years.
Apple Watch Series 12 gets the chip upgrade it needed
For years, Apple Watch was stuck on variations of the same aging chip. The Series 9, Series 10 and Series 11 were powered by the same architecture that traced back to the S9. Performance gains between generations were minor at best.
All that changes with the S11 chip in the Apple Watch Series 12 and Ultra 4. It’s derived from the A20 Pro silicon inside the new iPhone 18 Pro line, and brings the first real performance leap for the Apple Watch in half a decade. The S11 also enables on-device AI processing, which means a lot of your data stays local.
That extra processing power makes Apple Intelligence possible on the wrist. With watchOS 27, Siri gets rebuilt into a proper AI assistant. It understands personal context and taps into more knowledge. To top it off, a new Siri Modular watch face puts it a glance away.
A health sensing system with accuracy in mind
Apple says the Series 12 and Ultra 4 now offer the most accurate heart rate sensing of any wearable. That claim comes from a company study with more than 1,000 participants. Larger, more efficient green LEDs measure heart rate every five seconds around the clock, not just during workouts.
Heart rate variability tracking is more frequent now, measured up to 24 times more often than before. Apple also updated the Heart Rate app, which splits this into recovery HRV and overall HRV.
And a new daytime Vitals view lets you check for stress signals before they’d normally show up overnight.
All of that data is fed into Readiness, a new daily score that ranges from zero to 10. It factors in your recent activity, training load, sleep and vitals. Apple says Readiness is updated throughout the day. It gives you simple recommendations: recover, ready, pace yourself or go for it. That’s a pretty smart way to turn a pile of sensor data into something you’ll actually glance at every morning.
The Health app on iPhone is also getting a matching overhaul later this year. It’ll add a new Longevity tab and a Health Age score that compares your biomarkers to your actual age.
Apple is also rolling out $119 lab panels through nearly 2,000 Quest Diagnostics locations, which can be booked right from the Health app.
Audio Intelligence is now on your wrist
The built-in microphone on Series 12 and Ultra 4 powers what Apple calls Audio Intelligence. A fantastic-sounding Live Rewind feature lets you quickly double-press the crown to see a text transcript of the last 15 seconds of conversation. This means you won’t have to ask someone to repeat themselves.
And Siri Recap takes this a step further. It generates a title and key points from a conversation that you can review later in the Siri app. Sound Recognition is a new accessibility feature that lets deaf and hard-of-hearing users stay alert about things like doorbells, sirens, and alarms, even without an iPhone nearby.
And yes, Shazam can now identify songs straight from the Smart Stack.
Apple is leaning hard on privacy with the Apple Watch’s new Audio Intelligence features. No audio is recorded or stored on your watch. Processing happens inside an isolated hardware component called the Secure Exclave. Live Rewind and Siri Recap summaries are end-to-end encrypted, even from Apple itself.
The two features will be coming in beta later this year, and you can switch them off anytime from the Control Center.
Battery life and design get real upgrades too
Apple Watch Series 12 keeps its 24-hour everyday battery estimate. But it now stretches to 10 hours of outdoor workout tracking with GPS, a 25% jump over last year’s model. And 15 minutes on the charger now adds up to 12 hours of battery life.
Apple Watch Ultra 4 goes even further. It now offers more than two days of everyday battery life and can last up to 84 hours in Low Power Mode. The new Extended Workout and Max Extended Workout modes can track GPS workouts for up to 25 and 45 hours, respectively.
Design-wise, the Series 12 adds dark bronze and light gold aluminum finishes. A returning ceramic option is available in pearl white and night blue. As for aluminum models, they now use Ceramic Shield 2, which Apple says is 60% tougher than the old Ion-X glass.
Ultra 4 sticks with natural and black titanium.
Both watches are available for preorder today, ahead of a September 18 release.
How Series 12 stacks up against Series 11
The gap between Series 12 and last year’s Series 11 is bigger than Apple’s recent yearly updates. Series 11 shipped with the S10 chip. At its core, it’s the same silicon that powered the Series 9 and Series 10 before it. It never had the AI processing headroom Series 12 has.
Series 11 also measures heart rate periodically, not continuously every five seconds. It also misses out on Readiness, the redesigned Heart Rate app, and Audio Intelligence. And it lacks the Audio Intelligence features that the new S11 chip unlocks through the built-in microphone.
Anyone on Series 11 will get some watchOS 27 features, but the new sensor architecture and S11 chip are exclusive to the Series 12 and Ultra 4.
Old Apple Watch users, this is the upgrade to make
This is one of the best hardware upgrades the Apple Watch has had in years. The S11 chip alone justifies the jump. It also breaks Apple free from the S9-era bottleneck that’s held the Apple Watch lineup back since 2023.
Readiness, the smarter Heart Rate app, and Audio Intelligence round it up nicely, even if some features won’t land until later this year.
For anyone sporting an Apple Watch Series 8 or older, an upgrade seems even more important now. Those watches won’t get watchOS 27. So you’re not just missing out on new hardware; you’re locked out of the software update as well. If you’ve been waiting for a real reason to upgrade, Apple Watch Series 12 is finally it.
But Series 11 and Ultra 3 owners have a weaker case. Last year’s watches will get watchOS 27 and cover the basics well.
For everyone else, Series 12 starts at $399 and Ultra 4 at $799. Both are available to pre-order now, ahead of their September 18 launch.
Anurag Chawake is a tech-focused writer specializing in smartphones, apps and consumer technology. His interest in computers began during the Windows 98 era, eventually leading him to explore everything from operating systems to mobile devices and PC hardware. Anurag previously contributed to The Indian Express, covering Apple, Android, gaming and the broader technology landscape.
