Apple today announced the Apple Watch Ultra 4, featuring a new S11 chip, a redesigned health sensing system, and a larger battery that Apple says delivers two days of battery life.

With improved power efficiency, Ultra 4 offers up to 18 hours of workout tracking with full GPS and heart rate monitoring, or 45 hours in its maximum extended workout mode. It comes in Black and Natural titanium, alongside new band colors and a new titanium Hermès band.
The redesigned health sensing system features a larger electrode surface for improved skin contact during ECG readings, photodiodes arranged in a ring to capture light more efficiently, and larger, more power-efficient green LEDs for heart rate tracking.
More frequent readings are displayed in an updated Heart Rate app and new watch face complications. Apple says the system delivers the most accurate heart rate tracking of any wearable, citing a study involving hundreds of participants running, cycling, and performing HIIT workouts, with an ECG chest strap used as the reference.
A new Readiness feature analyzes recent activity, vitals, and sleep each morning to provide a score indicating whether users should recover, pace themselves, or take on more activity.
Apple is also redesigning the Health app to offer personalized guidance powered by Apple Intelligence. A new Health Age feature combines Apple Watch metrics such as VO2 max and sleep with blood test biomarkers to compare users’ health indicators with their chronological age. A Longevity tab brings together insights across sleep, movement, heart health, and other areas.
Users can enter lab results manually or sync their medical records. In the U.S., Apple will also offer access to a Quest blood panel covering more than 50 biomarkers for $119. A new VO2 max test uses the iPhone’s camera alongside Apple Watch to assess users as they perform a series of exercises, providing immediate results. The redesigned Health app is coming later this year.
The S11 chip’s energy-efficient always-on processor enables new Audio Intelligence features. Sound Recognition identifies sounds such as alarms, doorbells, and a baby crying, while Live Rewind displays a transcript of what was said in the preceding 15 seconds.
Siri Recap generates titles, summaries, and key points from conversations for users to review in the Siri app. Users can schedule when it takes notes or toggle it in Control Center. Apple says the audio features do not create or store audio recordings. Siri Recap will launch in beta later this year, initially in English, with additional languages to follow.
Apple Watch Ultra 4 starts at $799 and is available to preorder today, with availability beginning September 18.