Apple Watch Ultra 4 announced with S11 chip and Siri Recaps

The Apple Watch Ultra 4 keeps the same design as the Ultra 3 but swaps in the new S11 processor, which replaces the S10 chip introduced with the Series 10 in 2024. This chip is meant to handle the smarter Siri AI coming in watchOS 27, and it enables a new Recaps feature that uses the microphone to monitor activities and generate a summary of the day. The sensor improvements allow heart rate readings up to 60 times more frequently at 5-second intervals, and heart rate variability measurements every five minutes.

Adopting the Ultra 4 means paying at least $799 for the entry model, with a new Hermès version at a higher price. The Recaps feature is in beta and supports English only at launch, with additional languages to follow, and it can be scheduled to run only during work hours to limit nighttime use. The microphone-based monitoring raises privacy considerations, and the feature's accuracy in noisy environments is not addressed in the announcement.

The Ultra 4's improvements are mostly internal; the design is nearly identical to the Ultra 3, so the main differentiators are the processor and software. The battery life claims, over two days, up to 50 hours, and 84 hours in Low Power Mode, are under specific conditions, and the new Extended Workout modes trade off features for longer tracking. The Siri AI features depend on the upcoming watchOS 27 release, so they are not available at launch.

The announcement came at Apple's 'Surprise and shine' event, alongside other product updates. The Ultra 4 follows the Ultra 3, which had 5G, satellite messaging, and a larger display, but the new model focuses on performance and AI readiness rather than a hardware redesign. The S11 chip is positioned to support the more capable Siri AI that Apple introduced at WWDC earlier this year, making the Ultra 4 a platform for future software features.