Apple macOS Tahoe (26) Update Version macOS 26 SDK

macOS 26 SDK release notes for Tahoe 26, bundled with Xcode 26. Highlights include TextKit 2 behavior changes, new WebKit API loading support, and fixes for VideoToolbox, virtual machines, Weather, and Xcode Previews.

• Fixed a TextKit 2 paragraph indentation directionality issue caused by inconsistent hidden rules.
• Fixed high-bitrate HEVC decoding performance issues that could cause stuttering and lag.
• Fixed virtual machine networking failures when switching between bridge mode and shared or host mode VMs.
• Fixed a Weather tips issue where a blank white button could appear but still be operable.
• Fixed webViewOnScrollGeometryChange reporting an incorrect content size.
• Fixed Xcode Previews usage that frequently panicked on macOS 26.0 Tahoe beta 4.

• TextKit 2 adds includesTextListMarkers to control whether text list markers are included in attributed string contents.
• WebKit API load methods now return an AsyncSequence, and currentNavigationEvent has been replaced by navigations.
• WebKit API now supports directly loading URLs and provides a default baseURL when loading HTML strings.
• macOS Tahoe 26 introduces a new method for resolving natural and justified text alignment using base writing direction.
• AppKit adopts TextKit 2 text list behavior starting with macOS 26.

• For Catalyst apps using .translationTask(), buttons in the download approval UI might not work.
• WKPreferences.isLookToScrollEnabled is not available on non-visionOS platforms.

• The macOS 26 SDK is bundled with Xcode 26, available from the Mac App Store.
• For Xcode 26 compatibility requirements, see the Xcode 26 release notes.
• For Catalyst apps with .translationTask(), manually download needed languages in System Settings or build with the “Optimize for Mac” setting.
• Apps built with prior SDKs may retain older TextKit indentation behavior for binary compatibility.

• SwiftUI highPriorityGesture documentation
  https://developer.apple.com/documentation/swiftui/view/highprioritygesture(_:isenabled:)
• SwiftUI simultaneousGesture documentation
  https://developer.apple.com/documentation/swiftui/view/simultaneousgesture(_:isenabled:)

Product Information

Vendor: Apple

Product: macOS

Version: macOS 26 SDK

Release date: Sep 15, 2025