Apple Watch Series 12 and Ultra 4: Code leak hints at new sensor and 128 GB storage

The successors to the Apple Watch Series 11 and Ultra 3 ($879 on Amazon) are expected to be officially unveiled on Wednesday, September 9. MacRumors has now received specific clues from a reader regarding upgrades to the next-generation smartwatches, which are hidden in the code of the beta version of watchOS 27. 

The code includes several references to a new app called "Readiness," suggesting that Apple will place a greater focus on wellness and recovery features. This app is set to be positioned by default right next to the Workouts app in the new watchOS 27 home screen layout, though no further details about its functionality are known yet. The Workout app is expected to gain new features for tracking strength training, allowing users to log, for example, the weight and number of repetitions when using dumbbells.

Particularly exciting is that the watchOS 27 code contains references to a new optical heart rate sensor, which is said to offer a better signal-to-noise ratio, allowing for more precise heart rate measurement. Previous rumors have suggested that this sensor will make it possible to continuously monitor the heart rate, rather than taking a measurement only every few minutes. Finally, the code contains references to a Samsung NAND flash chip with 128 GB of storage, so it’s conceivable that Apple will include twice as much storage as before, at least in select models. The Apple Watch uses this storage primarily for apps, offline maps, and music stored directly on the smartwatch.