This overview summarizes the new features and points to note for the Apple Watch Series 12 and Ultra 4 confirmed on site at the launch event. It focuses on expanded health features, including high-frequency heart rate and HRV measurements and Readiness, as well as when they will become available in Japan.
Apple has adopted a design for the Watch Series 12 and Ultra 4 that builds on previous models while providing more detailed health data. A new electrode arrangement using petal-shaped electrodes on the back, together with optical sensors arranged in a ring, improves the stability and accuracy of heart rate measurements. The aim is to provide a more detailed view of users’ day-to-day health.
Heart rate measurements have shifted from the previous 5-minute interval to every 5 seconds, while the frequency of HRV measurements has increased by up to 24 times. The feature was presented as a way to track stress and recovery in daily life from two perspectives: recovery HRV and overall HRV. The new Readiness feature also analyzes recent activity, sleep scores and vitals, then displays the day’s capacity for activity as a score from 0 to 10 and across 4 levels.
The Series 12 is rated for up to 24 hours of normal use, up to 10 hours of outdoor workouts and 12 hours of normal use after a 15-minute charge. The Ultra 4 can deliver up to 50 hours of normal use, up to 84 hours in Low Power Mode and up to 45 hours in extended workout mode. Improved step-counting accuracy was also highlighted.
The core new features in Japan, including heart rate and HRV measurements, Readiness and daytime vital signs, are expected to be available from the launch date. However, Japanese-language support for Siri AI features is scheduled for October, while Workout Buddy will support only English and Spanish. Some voice-related new features had not yet been fully explained or demonstrated on site.