Apple Unveils Apple Watch Series 12 with Health Sensing System and S11 Chip

Apple has unveiled the Apple Watch Series 12, introducing the S11 chip, which is considered the most powerful chip ever in a wearable, and a new health sensing system. This model focuses on significantly improving the accuracy and measurement frequency of health metrics such as heart rate, HRV, and readiness.

Health Sensing and Battery Performance

The new health sensing system was developed based on research data from over 1,000 people and measures heart rate every 5 seconds using larger, more efficient green LEDs. The frequency of HRV (Heart Rate Variability) measurements has increased by up to 24 times, and nighttime vitals now include recovery HRV compared to personal baselines. It also analyzes activity, training load, and sleep scores to provide a readiness score from 0 to 10. Battery life lasts up to 24 hours during typical use, and fast charging provides up to 12 hours of use in just 15 minutes, a 50% improvement over the previous model.

AI Features and watchOS 27

watchOS 27 will be released on September 14, introducing Siri AI powered by Apple Intelligence. Siri AI utilizes personal context and world knowledge; the English beta is available on September 14, with support for 16 languages including Korean expected in October. The audio intelligence feature, utilizing the built-in microphone and S11 chip, processes siren detection and Shazam support on-device, with recordings not being stored but immediately deleted. Step tracking accuracy has also been improved with a new ML algorithm based on the S11 chip.

Design, Pricing, and Limitations

The design is available in two sizes, 42mm and 46mm, with aluminum models featuring Ceramic Shield 2, which is 60% tougher than the previous Ion-X glass. The launch price in Korea starts at 599,000 KRW, with pre-orders opening on September 11 and official release on September 18. However, the hypertension notification feature will not be available in Korea initially and is scheduled for an update later this year. Battery and performance data are based on prototypes from July–August 2026.