watchOS 26.4 Release Notes
Update your apps to use new features, and test your apps against API changes.
Overview
The watchOS 26.4 SDK provides support to develop watchOS apps for Apple Watch devices running watchOS 26.4. The SDK comes bundled with Xcode 26.4, available from the Mac App Store. For information on the compatibility requirements for Xcode 26.4, see Xcode 26.4 Release Notes.
Address Sanitizer
Known Issues
Address Sanitizer and Thread Sanitizer might hang on macOS 26.4, iOS 26.4, tvOS 26.4, watchOS 26.4, and visionOS 26.4 when building with Xcode 26.3 or older. (171762808)
Workaround: Use Xcode 26.4 when testing applications with Address Sanitizer or Thread Sanitizer.
Apple Maps
Known Issues
Directions might fail to load on Watch when the companion iPhone is connected. (168923852)
Workaround: Start directions from the companion iPhone.
Movement Disorder API
Resolved Issues
Fixed: The Movement Disorder API has enhanced analytics around database access errors. (129771567)
Networking
Resolved Issues
Fixed: Multiple processes leak
CFRunLoopSourceobjects when Automatic proxy configuration (PAC) or Auto proxy discovery are configured.For clients of the
CFNetworkExecuteProxyAutoConfigurationURLandCFNetworkExecuteProxyAutoConfigurationScriptAPI, please check to make sure your process is not working around the leak by overreleasing theCFRunLoopSourceRefreturned by those functions or theCFArrayRefandCFErrorRefpassed to the completion. (166839810) (FB21376045)
StoreKit
New Features
New fields revocationType and revocationPercentage have been added to Transaction. (148858551)
Resolved Issues
Fixed: Purchase Intents might not be emitted from the intents sequence when the app is launched from the background. (168958783) (FB21767675)
SwiftUI
Resolved Issues
Fixed: SwiftUI does not surface the latest
.userActivityas the current user activity. (163136831)
Workout
Resolved Issues
Fixed: When you start a workout with Workout Buddy enabled, the timer might appear to be delayed by a few seconds before it starts counting. (169030068)