Apple Watch Series 12 and Ultra 4 are now shipping to customers, with initial reviews praising the new Health Sensing System that delivers the most accurate heart rate tracking in a wearable to date. The watches, announced at Apple's 'Surprise and shine' event, are powered by the S11 chip and are preparing for a smarter Siri AI assistant expected with watchOS 27.
The Apple Watch Series 12 and Ultra 4 have begun arriving on wrists, following preorders that opened September 9 and general availability starting September 18. Both models retain the same pricing as their predecessors — the Series 12 starts at $399 for aluminum, $699 for titanium, and $899 for ceramic cases, while the Ultra 4 starts at $799.
First reviews highlight the new Health Sensing System as the standout feature. The system uses redesigned photodiodes arranged in a ring, larger green LEDs, and a bigger electrode surface area to capture light more efficiently. Apple claims this setup enables the 'most accurate heart rate sensing in a wearable,' with heart rate measured every five seconds. Users can now view their live heart rate as a watch face complication, along with new live steps count and readiness score complications exclusive to the new models.
A reviewer from 9to5Mac noted that the live heart rate data 'has been an essential new complication' and that step tracking has been 'a big motivator for getting activity logged earlier in the day.' Battery life is also improved: the Series 12 offers up to 24 hours of everyday use and up to 10 hours during outdoor workouts with faster charging, according to The Verge.
Under the hood, the S11 chip replaces the S10 chip introduced in 2024, bringing performance improvements ahead of the upcoming watchOS 27 release. That update will include a more capable Siri AI assistant, first previewed at Apple’s WWDC earlier this year. The Ultra 4 retains a nearly identical rugged design to the Ultra 3.
No update to the Apple Watch SE was announced for 2026. Third-party retailers are already offering discounts on the new models, with some configurations seeing up to $325 off through preorder deals, according to 9to5Mac.
Analysis
Why This Matters
- Apple Watch buyers considering an upgrade will find the new Health Sensing System the most compelling reason to move from Series 11 or earlier, as it offers genuinely new real-time heart rate data previously unavailable on the wrist.
- The S11 chip positions both watches for the upcoming Siri AI overhaul, meaning the 2026 models may gain significantly more utility over their lifespan compared to older hardware that won't support the new assistant.
- Battery life improvements — up to 10 hours of outdoor workout tracking — address a key pain point for athletes and outdoor users.
Background
The Apple Watch is the dominant smartwatch globally, with Apple releasing annual updates to its standard Series line and its rugged Ultra line aimed at outdoor enthusiasts and athletes. The Series 12 and Ultra 4 launch in a market where health tracking and AI features are increasingly central to wearable competition, with rivals like Samsung and Garmin also advancing their sensor arrays. The new Siri, expected in watchOS 27, promises to bring on-device processing and more contextual capabilities, following a trend toward AI-powered assistants across Apple’s ecosystem.
Key Perspectives
Apple: Positions the new watches as a health upgrade with the most accurate heart rate sensing available, and as a platform ready for the next generation of AI-powered Siri capabilities.
Consumers: Gain access to real-time health data and an improved user experience, but must weigh whether the upgrades justify the purchase over existing models, especially given no price changes.
Critics/Skeptics: The design remains nearly identical year over year, and the new features may feel incremental to users who don't heavily use health tracking or plan to upgrade to watchOS 27 regardless.
What to Watch
- Whether the new Siri in watchOS 27 ultimately requires the S11 chip, making the Series 12 and Ultra 4 the only eligible devices for the AI assistant.
- Consumer adoption of the live heart rate complication as a differentiator in daily use.
- Third-party discount depth: if deals remain strong, they may signal lower-than-expected demand or strong retailer competition.