Apple unveils Apple Watch Ultra 4 with S11 chip, new health sensing and up to 50-hour battery life

Apple has unveiled Apple Watch Ultra 4, introducing a new Health Sensing System, the S11 chip, longer battery life and a collection of new health, fitness and Apple Intelligence features.

The fourth-generation Ultra keeps the familiar rugged titanium design and is available in natural and black finishes, but Apple has reworked several of the technologies inside. The company says the new model delivers its most accurate heart-rate sensing in a wearable, alongside higher-frequency heart rate and heart rate variability measurements.

Apple Watch Ultra 4 also introduces Readiness, which combines recent activity, training load, vitals and sleep information into a daily score between zero and 10. The watch then offers one of four recommendations: Recover, Pace Yourself, Ready or Go For It.

The new Health Sensing System uses redesigned optical and electrical heart sensors alongside the S11 chip. Heart rate is now measured every five seconds throughout the day, while HRV can be measured up to 24 times more frequently than before.

Apple has also overhauled battery performance. Ultra 4 is rated for up to 50 hours during everyday use and up to 84 hours in Low Power Mode. A new Max Extended Workout mode can track outdoor runs, walks and hikes for as long as 45 hours while continuing to take GPS readings every second.

Charging is faster too, with Apple saying a 15-minute charge can provide up to 18 additional hours of battery life.

Fitness tracking has received further attention. Apple says a redesigned pedometer model and new machine-learning algorithms make Ultra 4 its most accurate Apple Watch for step counting, while the company also claims the device offers the most accurate on-device GPS in a sports watch.

The S11 chip enables Apple’s new Audio Intelligence features, including Sound Recognition, Live Rewind, Siri Recap and faster Shazam. Live Rewind can display a text snippet covering the previous 15 seconds of a conversation, while Siri Recap can generate short summaries of conversations for users to revisit later. Live Rewind and Siri Recap are scheduled to arrive in beta later this year.

With watchOS 27, Apple Watch Ultra 4 also supports Siri AI, bringing personal-context understanding and broader world knowledge to Apple’s wearable. Other watchOS 27 additions include a dynamic app grid, new single-handed tap gesture, smarter Smart Stack suggestions and expanded Workout Buddy support.

The Health app on iPhone is being redesigned later this year with Insights and Longevity tabs. Health Age will use Apple Watch data to show how selected health metrics compare with a user’s actual age.

Apple Watch Ultra 4 is available to pre-order today and will be released on Friday, September 18. Pricing starts at $799 in the United States.

Apple is also introducing refreshed Trail Loop, Alpine Loop and Ocean Band colors, while the Apple Watch Hermès Ultra 4 gains a new Grand H titanium band designed with an extension mechanism that allows it to fit over a wetsuit.