Apple opens preorders for Watch Series 12 and Ultra 4 with new Health Sensing System

Apple began preorders for the Watch Series 12 and Watch Ultra 4. Both run watchOS 27, use the new S11 chip, and introduce what Apple calls a Health Sensing System intended to increase the frequency and apparent accuracy of heart-rate and heart-rate variability (HRV) measurements.

Concrete user-facing measurement changes

• Heart rate updates every five seconds and can be shown in real time with a dedicated heart rate watch face complication.
• HRV measurements can be collected up to 24 times more frequently than on earlier Apple Watches, according to Apple. Recovery HRV is now compared to a user's personal baseline.
• Overnight vitals will include recovery HRV analyzed against that baseline. A daytime vitals view lets users switch between overnight and daytime metrics to spot shifts earlier.

Readiness score and Health app additions

Apple adds a readiness score that analyzes recent activity, training load, vitals, and sleep score to estimate a user's capacity for the day on a 0–10 scale. The score updates throughout the day based on activity.

The iOS Health app will be updated later this year to include a Health Age metric and movement evaluations that measure flexibility, strength, balance, and more using iPhone vision-based models plus Apple Watch heart-rate data. Apple will also offer lab tests inside the Health app: users can schedule and purchase lab panels covering more than 50 biomarkers for $119 at roughly 2,000 Quest Diagnostics locations in the US.

Apple Intelligence features on the watches

Both models include Apple Intelligence features integrated into watch functionality. Examples Apple highlighted include Shazam song detection on the watch, Live Rewind (a quick way to show the prior 15 seconds of a conversation as a text snippet when the Digital Crown is double-pressed), and Siri Recap, which creates high-level summaries of conversations.

Series 12 will be available in aluminum, titanium, and optional ceramic finishes with new colors. Apple says the aluminum versions are 60 percent tougher than previous aluminum models. Ultra 4 comes in natural and black titanium finishes.

Both watches are available for preorder now and will ship on September 18. Pricing starts at $399 for the Watch Series 12 and $799 for the Watch Ultra 4.

Look for the updated Health app roll-out later in the year, documentation about the accuracy study if you want to judge Apple's claim scientifically, and any third-party testing that compares continuous heart-rate and HRV sampling against clinical references.