Xcode 15.3 adds SwiftConcurrency visual debugger and a rebuilt SwiftUI Inspector

Design · 5 min read

Xcode 15.3 introduces a visual SwiftConcurrency debugger that displays tasks, actors, and continuations in a timeline view, making it easier to spot deadlocks and performance hotspots. The tool can collapse common patterns like async await chains and highlight priority inversions, while providing one-click snapshots of task-local state.

The new SwiftUI Inspector surfaces design tokens, spacing systems, and color roles in a side panel that maps directly to live views; changes propagate to simulators without full rebuilds. Designers can now inspect a component’s variant states and the underlying layout constraints, and export a token snapshot for handoff.

Build system improvements focus on incremental compilation for Swift packages and previews, and the release adds a template for Live Widget previews. Apple also updated documentation and sample projects to show best practices for combining SwiftConcurrency with SwiftData and SwiftUI.