Apple unveils Apple Watch Ultra 4

Apple Watch Ultra 4 introduces a new Health Sensing System and S11 chip, delivering the most accurate heart rate sensing in a wearable. The device measures heart rate every five seconds using larger green LEDs, providing deeper insights into fitness and physiological state. Users can view real-time heart rate via a new watch face complication, while HRV measurements are now available up to 24 times more frequently. The system includes two HRV variants—recovery and overall—to better assess stress, recovery, and cardiovascular health.

The watch introduces a readiness score, analyzing activity, training load, vitals, and sleep to offer a daily 0-10 rating with actionable recommendations. Readiness updates throughout the day, highlighting factors influencing the score. The feature was developed using data from the Apple Heart and Movement Study, in collaboration with exercise scientists and physicians. The redesigned Health app on iPhone will include a new Longevity tab with a Health Age feature later this year.

Apple Watch Ultra 4 extends battery life to over two days, with up to 50 hours in regular use and 84 hours in Low Power Mode. Charging takes just 15 minutes for up to 18 hours of additional battery life. For outdoor workouts, the Extended Workout mode offers up to 25 hours of tracking, while the Max Extended Workout mode supports up to 45 hours, suitable for events like 100-mile races.

The S11 chip powers new Audio Intelligence features, enabling users to stay alert to important sounds and remember key conversation moments. The redesigned Health app will include movement evaluations using vision-based AI and heart rate data, while lab tests with over 50 biomarkers can be scheduled for $119 at Quest Diagnostics locations in the U.S. The watchOS 27 update brings Apple Intelligence-powered Siri to the wrist.