Apple unveils Apple Watch Series 12 and Ultra 4 with new health sensing system

Apple has introduced the Apple Watch Series 12 and Apple Watch Ultra 4, both of which incorporate a redesigned Health Sensing System. The new hardware includes larger electrodes, increased photodiode surface area for improved light capture, and larger, more power-efficient green LEDs. According to Apple, this architecture allows for heart rate monitoring every five seconds and heart rate variability (HRV) sampling every five minutes, which the company claims provides the most accurate heart rate sensing currently available in a wearable device.

Powering both models is the new S11 chip, which Apple describes as its most powerful wearable processor to date. The chip integrates components derived from the A20 Pro, including updated CPU, GPU, and Neural Engine architecture. This processing power enables new Audio Intelligence features, such as Sound Recognition for environmental alerts like doorbells or alarms, and a Live Rewind function that allows users to transcribe the previous 15 seconds of speech by interacting with the Digital Crown.

The Apple Watch Series 12 introduces a ceramic body option alongside traditional metal finishes and features Ceramic Shield 2 glass for increased durability. The Apple Watch Ultra 4 retains its focus on sports and adventure, offering up to two days of battery life. In maximum extended workout mode, the Ultra 4 is rated for up to 45 hours of tracking with active GPS and heart rate monitoring. The device is available in black and natural titanium finishes.

Software updates arriving later this year include a redesigned Health app featuring a Longevity tab and a Health Age metric, which correlates sleep and movement data with blood biomarkers. A new Readiness score will also be available, synthesizing activity, vitals, and sleep data to help users determine their recovery needs. Additionally, Siri Recap will provide summaries of meetings and conversations, with the company noting that these audio features are designed to function without storing actual audio recordings.

Pricing for the Apple Watch Series 12 starts at $549 in Canada, while the Apple Watch Ultra 4 begins at $1,099. In the United States, the Series 12 starts at $399 and the Ultra 4 at $799. Both models are available for pre-order immediately, with retail availability scheduled to begin on September 18.