what new in swift 2026

Here are the main new things in Swift for WWDC 2026, based on What’s new in Swift and the Swift section in Platforms State of the Union:

Language and compiler improvements

• anyAppleOS availability: you can now condense Apple platform availability checks into a single platform name instead of repeating multiple OS names.
• @diagnose attribute: new tooling for improving diagnostics.
• Module selectors (::): new syntax for accessing members across modules.
• Better type checking performance: especially for complex expressions and SwiftUI View bodies, with more actionable errors when type checking struggles.
• Async in defer now works: the limitation on awaiting inside defer blocks is removed.

Everyday workflow improvements

• Warning control: you can suppress warnings in specific parts of code or promote warnings to errors where you want stricter enforcement.
• More flexible memberwise initializers: structs with a mix of internal and private properties now get a second memberwise initializer usable from other files in your project.

Libraries and APIs

• Swift Testing updates
• Subprocess 1.0
• Foundation updates
• New standard library additions

Swift across more platforms

• Swift–C interoperability improvements with @C attribute
• Swift-Java
• WebAssembly and JavascriptKit
• Embedded Swift continues to expand
• More work on beyond Apple platforms

Performance and advanced language features

• Performance tuning
• Optimizer control with:
  • @inline(always)
  • @specialized
• Ownership system and noncopyable types
• Iterable protocol and borrow/mutate accessors
• New standard library types like UniqueBox, UniqueArray, and Ref

Future direction

• The session also covers the future of Swift, including ongoing open-source work and ecosystem development.

If you want, I can also give you a short “top 5 changes” summary or a section-by-section breakdown with timestamps.