Apple Watch Series 12 and Ultra 4 review: new colors and materials, revamped Health Sensing System, an S11 chip, and future AI features, but few design changes

Your Apple Watch now tracks heart rate and HRV more frequently, offering deeper insights into daily stress and recovery.

Apple has released the Apple Watch Series 12 and Apple Watch Ultra 4, featuring a revamped Health Sensing System and an S11 chip, with new colors and materials. The design remains largely the same as previous models, though the Series 12 sees minor dimensional changes and new material options including aluminum with Ceramic Shield 2, titanium in Radiant Gold, and ceramic in Pearl White and Night Blue. The Ultra 4 continues with titanium finishes. The most significant update is the Health Sensing System, which includes redesigned electrodes for better ECG contact, improved photodiode arrangement for more light capture, and larger, more efficient green LEDs. This allows for more frequent and accurate background heart rate measurements (every five seconds) and higher-rate heart rate variability (HRV) sampling (every five minutes at rest). New features include a readiness score, a daytime Vitals view, and improved calorie estimates, alongside enhanced analysis of heart rate and HRV data to better track stress and fatigue.

The Apple Watch Series 12 and Ultra 4 significantly advance health monitoring with a new Health Sensing System, primarily through more frequent and accurate heart rate and heart rate variability (HRV) tracking. This deeper data collection aims to provide users with a more granular understanding of their body's daily responses to stress, activity, and fatigue. The integration of a readiness score and an expanded Vitals app, including a daytime view, further distills this complex data into actionable insights for users aiming to optimize their well-being.

This enhanced health tracking capabilities signal a market trend towards wearables as proactive health management tools rather than just fitness trackers. By leveraging more frequent sensor data and sophisticated algorithms, Apple is positioning its watches to offer more predictive health insights, potentially influencing user behavior around rest, recovery, and overall lifestyle choices. Competitors will likely face pressure to match these advanced sensing and analytical features to remain competitive in the increasingly health-focused wearable technology sector.