Apple Watch Series 12 and Ultra 4 Last-Minute Leak: Readiness App, 128GB Storage, New Chip, and Ceramic Return

A code leak published on September 7 has revealed four significant additions coming to the Apple Watch Series 12 and Apple Watch Ultra 4, just one day before Apple's "Surprise and Shine" event on September 9. MacRumors forum member pdfu discovered references in Apple's code pointing to features that expand on earlier reports from Bloomberg's Mark Gurman.

The Four New Features

• Readiness App: An all-new standalone Watch app separate from the existing Vitals app, referred to in Apple's code as "Readiness." Health-focused and linked to the Workout app, it suggests Apple is building a Whoop/Oura-style daily readiness score directly into watchOS 27.
• 128GB Storage: A NAND storage profile tied to the T8320 chip suggests both watches will double storage from 64GB to 128GB — useful for offline music, podcasts, and on-device health data.
• New T8320 Processor: The most significant hardware change in years. The Apple Watch Series 11, Ultra 3, and SE 3 all used the same S10-generation silicon. The 2026 models finally move to a new chip, promising better performance and efficiency.
• Ceramic Cases: White and dark gray ceramic options are returning to the Apple Watch for the first time since the Series 3 in 2017. Ceramic is harder and more scratch-resistant than aluminum or stainless steel.

What Else to Expect Tomorrow

Beyond these four features, earlier leaks point to blood pressure notification technology under FDA review (possibly Ultra 4 only), continuous all-day heart rate monitoring, and a revamped Health app with Whoop-style recovery dashboards. Two AirPods 5 models with the H3 chip are also expected.

What Buyers Should Know

If you've been waiting for the Apple Watch Series 12, this leak confirms the upgrade is more substantial than initial reports suggested. The combination of a new chip, doubled storage, and the Readiness app makes it the biggest year-over-year Apple Watch update since Series 8. Current Apple Watch Series 11 owners may want to wait 24 hours before buying — the Apple Watch Ultra 3 is likely to see price drops once Ultra 4 is announced. Compare all options in our smartwatch guide.