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.
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.
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.
In-depth guide
SwiftUI & Liquid Glass in iOS 27 →iOS 27 enforces stricter adaptivity requirements for UIKit apps, making iPhone apps fully resizable in iPhone Mirroring and on iPad, while introducing new navigation bar minimization controls, sidebar opt-in for iPhone tab bars, and prominent tab customization.