Apple has released iOS 26.4 beta 3, giving developers an updated SDK to test upcoming features and API changes before the public release. The update ships with the iOS & iPadOS 26.4 SDK, bundled with Xcode 26.4, and allows developers to build and test apps for iPhone and iPad running the latest beta software.
While this beta does not introduce major consumer facing changes, it includes several notable developer improvements across Messages, StoreKit, networking, and asset management. Apple has also added new security capabilities for apps and begun early testing of RCS end to end encryption between iPhone and Android devices.
One of the more notable additions in iOS 26.4 beta 3 is early testing support for RCS end to end encryption in the Messages app. Apple says this encryption layer is currently in beta and available only for testing between Apple and Android devices.
Encrypted conversations will be labeled accordingly and are protected end to end, meaning messages cannot be read while being transmitted between devices. Apple notes that the feature is not shipping to customers yet and will roll out in a future release of iOS, iPadOS, macOS, and watchOS 26. Availability will also depend on device and carrier support.
Developers are also getting additional ways to manage on demand asset packs when devices are offline. Two new methods allow apps to check whether asset packs are already stored locally without requiring a network connection.
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Developers can check detailed status information using
localStatus(ofAssetPackWithID:). -
A simpler synchronous method
assetPackIsAvailableLocally(withID:)returns a Boolean value indicating local availability.
Apple has also added a new method that allows developers to ensure the latest version of an asset pack is stored locally. By calling ensureLocalAvailability(of:requireLatestVersion:) with the update parameter enabled, apps can automatically fetch the newest version when needed.
iOS 26.4 beta 3 also expands Memory Integrity Enforcement for applications. Developers can now opt in to full protection for stronger memory safety. Previously, applications were limited to Soft Mode. The new option gives developers the ability to adopt stricter protections that help reduce certain memory related vulnerabilities.
StoreKit also receives a small update in this beta. Apple added two new properties to the Transaction object that provide more details when transactions are revoked or partially refunded.
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revocationType -
revocationPercentage
Several issues across system frameworks have also been resolved. Apple fixed a problem where Purchase Intents might not be emitted correctly when an app launches from the background. A networking issue that caused multiple processes to leak CFRunLoopSource objects when automatic proxy configuration was enabled has also been addressed.
Additional fixes were rolled out across SwiftUI and UIKit. SwiftUI now properly surfaces the latest user activity, while UIKit resolves a bug where KeyboardNotification might fail to send.
As with most beta releases, there are still a few known issues developers should be aware of while testing. Apps may occasionally crash when downloading asset packs, though relaunching the app typically restores access to the asset pack that was being downloaded.
Reality Composer on iOS also currently cannot export projects as .reality or .usdz. Attempting to export opens an empty panel instead.
Apple also notes a limitation with certain SwiftUI implicit animations. When multiple animations modify overlapping component properties, the most recently initiated animation may overwrite earlier ones unless the same properties are targeted.
