What's new in Xcode?

What's New in Xcode 16

Xcode 16 introduces several exciting new features and improvements across various aspects of app development. Here are some of the key updates:

1. Code Completion:

   • Xcode 16 features a new code completion engine powered by a specialized coding model trained specifically for Swift and Apple SDKs. This engine uses surrounding code context to provide more accurate suggestions and runs locally on your Mac, ensuring privacy and fast results. This is made possible by Apple silicon and is available on macOS Sequoia.
   • Platforms State of the Union (21:25)

2. Swift 6:

   • Swift 6 introduces a new language mode that provides concurrency safety guarantees, turning data races into compile-time issues, which improves the correctness and safety of your code.
   • What’s new in Xcode 16 (01:01)

3. Previews:

   • Xcode Previews now use a new dynamic linking architecture that avoids rebuilding your project when switching between previews and builds, resulting in a smoother workflow. A new previewable macro allows the use of dynamic properties like state directly in previews.
   • Platforms State of the Union (37:45)

4. Builds:

   • Xcode 16 introduces explicit modules for C and Objective-C by default, and for Swift with an opt-in. This feature improves parallelism, diagnostics, and debugging without changing any code.
   • What’s new in Xcode 16 (06:26)

5. Debugging and Performance:

   • The thread performance checker now includes diagnostics for excessive disk writes and slow app launches, helping you prioritize and fix performance issues.
   • The organizer now shows the impact of issues across different app versions, helping you track and prioritize fixes.
   • What’s new in Xcode 16 (09:10)

6. Swiftassist:

   • Swiftassist is a new feature that leverages a powerful model running in the cloud to assist with coding tasks, such as answering coding questions and experimenting with new APIs.
   • Platforms State of the Union (26:38)

7. Instruments and Profiling:

   • Xcode 16 introduces a flame graph for profiling data in Instruments, providing deeper insights into your app's performance.
   • What’s new in Xcode 16 (19:44)

8. Localization:

   • Enhancements to localization catalogs make it easier to bring your app to more people around the world.
   • Platforms State of the Union (26:38)

For a comprehensive overview, you can watch the full session on What’s new in Xcode 16 (00:07).