Apple Watch Series 12 and Ultra 4 leak points to four new features

Code in the watchOS 27 and iOS 27 betas may have revealed four changes coming to Apple’s next watches. A MacRumors forum post from user pdfu points to a new Readiness app, more detailed strength-workout tracking, a revised optical-sensing system, and possible 128GB storage.

Apple has not confirmed any of them. The clues also do not prove that every feature will arrive on both the Apple Watch Series 12 and Apple Watch Ultra 4.

A new Readiness app may sit beside Workout

The beta code refers to a separate Apple Watch app called Readiness. It appears in the watchOS launcher logic and in the iPhone Watch app’s code for arranging the default Home Screen, where it sits next to Workout.

That name suggests a broader recovery or wellness view, separate from the existing Vitals app. The code does not explain what data Readiness would show or whether it would be exclusive to the new watches.

Strength workouts could track each set

Apple is also preparing health data structures that can store more detail about strength training. The fields include individual sets, repetitions, weight, equipment, body side, and workout duration.

That would give the Workout app a better record of how a session was performed instead of treating strength training as one broad activity. The code points to the data model, not a finished screen or a confirmed watchOS 27 feature.

The optical sensor may get a hardware update

Another clue is a sensor family called "Sunstone4p0." The code describes lower noise coefficients and channel selection based on the watch’s position and orientation.

In plain terms, that could help the watch choose a better sensing path when the reflected pulse signal is weak or when the watch sits differently on the wrist. It may point to revised heart-sensing hardware, but the code does not identify the final component or the model that will use it.

128GB storage is possible, not guaranteed

The code also contains a NAND storage profile tied to the T8320 chip that is associated with the Series 12 and Ultra 4. That has led to speculation that Apple could double Apple Watch storage from 64GB to 128GB.

The benefit would be more room for music, offline content, apps, and future on-device features. Most buyers probably will not need that much space, though, and the storage profile does not prove that Apple will offer 128GB on every configuration. A current Apple Watch buying guide shows how the existing lineup is positioned today.

The launch is still unconfirmed

Apple’s September 9 event is the likely place to learn whether these features are real. Separate reporting has also tied the event to the Series 12 and Ultra 4, including another Apple Watch Ultra 4 rumor about sensors and health alerts.

Until Apple shows the watches or publishes their specifications, the safest read is that the beta code reveals what the company is testing, not what every customer will get.