Apple is preparing a fundamental architectural change for its smartwatch platform, with watchOS 26 set to transition newer Apple Watch models to a complete 64-bit computing foundation. The update will move the Apple Watch Series 9, Series 10, and Ultra 2 from the specialized arm64_32 architecture to the standard arm64 framework used across Apple’s other devices.
The company disclosed the technical shift in developer materials released this week, highlighting how the change will enhance app performance and development consistency. The outgoing arm64_32 architecture – a hybrid design using 64-bit processing with 32-bit memory addressing – was originally implemented to balance performance with the constrained memory resources of wearable devices.
Performance Gains and Development Adjustments
The transition brings several key advantages:
- Expanded memory addressing capabilities
- Full compatibility with modern ARM computing standards
- Better alignment with Apple’s unified development environment
- Support for more sophisticated watchOS applications
Developers will need to maintain dual compatibility during the transition period, as older models including the Apple Watch SE (2nd generation) and Series 8 will continue using arm64_32. Apple’s Xcode development tools will automatically handle the necessary build configurations when developers properly set their deployment targets.
Phased Transition Strategy
While existing arm64_32 apps will remain functional on new hardware through a compatibility layer, Apple strongly encourages developers to recompile their applications for native arm64 support. This recommendation comes as the company signals its long-term direction – all other Apple platforms have already completed the move to arm64, suggesting watchOS will eventually follow suit completely.
The architectural update represents one of the most significant under-the-hood improvements to Apple Watch capabilities in recent years. By adopting the same computing foundation as iPhones, iPads and Macs, the wearable platform stands to benefit from improved development tools, better performance, and more sophisticated applications.
watchOS 26 is expected to launch this fall alongside new Apple Watch hardware releases and iOS 18. The update continues Apple’s pattern of extending the capabilities of its wearable platform while maintaining support for recent older models.
