iOS 27 brings a sweeping set of SwiftUI enhancements including Liquid Glass design adoption, new toolbar visibility and overflow APIs, document architecture improvements with Observable, and resizable iPhone app support — all designed to modernize app UIs with minimal code changes.
• Liquid Glass design is automatically applied to SwiftUI apps on 2027 OS releases with no code changes required
• New toolbar APIs: visibilityPriority modifier, ToolbarOverflowMenu container, and topBarPinnedTrailing placement replace manual workarounds for toolbar overflow
• Document API expanded: WritableDocument/ReadableDocument protocols with DocumentWriter/DocumentReader and nonisolated async write support replace FileDocument for document-based apps
• toolbarMinimizeBehavior(.onScrollDown) and prominentTab role added for richer navigation UX
• Liquid Glass design is automatically applied to existing SwiftUI apps with zero code changes, while new toolbar APIs (visibilityPriority, ToolbarOverflowMenu, topBarPinnedTrailing) give fine-grained control over what stays visible as windows resize
• The new DocumentGroup architecture with WritableDocument/ReadableDocument protocols and Observable integration enables high-performance, background-safe file I/O with granular progress reporting
• iPhone apps become resizable in iOS 27, and Xcode 27 Live Previews gain resize handles — making it essential to audit existing layouts for adaptive behavior
Liquid Glass is Apple's new material and visual design language introduced in iOS 27, bringing translucent, refractive glass-like surfaces to system and custom UI elements. It replaces the frosted vibrancy aesthetic with a more dynamic, depth-aware material that responds to content beneath it.
PaperKit is Apple's full-featured canvas framework — previously internal-only — now publicly available in iOS/macOS/visionOS 27. It powers the drawing and markup experience in Notes, Preview, and Freeform, giving developers access to a complete pencil, shapes, images, and text canvas with a rich data model.
Xcode 27 introduces a fully customizable toolbar and theme system, untitled scratch projects, coding agent integration directly in the editor, and the new Device Hub for evaluating apps across simulators and physical devices side-by-side.
In-depth guide
SwiftUI & Liquid Glass in iOS 27 →iOS 27 introduces new SwiftUI drag and drop APIs including reorderable, reorderContainer, dragContainer, and configuration modifiers that enable reordering within and across collections, multi-item drag, and fine-grained control over how data is transferred during drag and drop operations.