Liquid Glass is a design language and dynamic visual material developed by Apple for its graphical user interfaces. Introduced on June 9, 2025, it combines translucent surfaces with simulated reflection, refraction, and fluid transformations. It formed the basis of a coordinated redesign announced for iOS 26, iPadOS 26, macOS Tahoe 26, watchOS 26, and tvOS 26. The term describes a software-rendered appearance and behavior, not a physical glass material. (apple.com)
Origins and scope
Apple presented Liquid Glass at its 2025 Worldwide Developers Conference. The company identified the depth and dimensionality of visionOS as an inspiration for the redesign. Its developer presentation also traced influences through the Aqua interface of Mac OS X, the real-time background blurring introduced in iOS 7, the gesture-driven fluidity of iPhone X, and the shape-changing Dynamic Island. Rather than reproducing an ordinary physical substance, Apple described Liquid Glass as a digital material whose optical appearance and movement can change with context. (apple.com)
The redesign extended beyond individual buttons to navigation bars, sidebars, system controls, app icons, widgets, and other system surfaces. Its stated purpose was to establish greater consistency across Apple’s operating systems while retaining platform-specific characteristics. Apple also introduced Icon Composer for constructing layered app icons with light, dark, tinted, and clear appearances. (apple.com)
Visual and interactive characteristics
Optical effects
Liquid Glass uses real-time computer graphics to create the impression of a translucent object floating above other interface elements. Background content influences its color, while highlights and shadows help define its boundaries. A central effect is lensing: the apparent bending of underlying imagery near a surface’s contours, which communicates shape and separation without requiring a fully opaque background. (apple.com)
The effect is more than a transparent fill. Apple’s implementation blurs underlying content, reflects surrounding colors, and responds to touch and pointer interactions. These properties are combined with changes of shape and transitions between related controls. Custom elements can move, merge, and morph into one another rather than merely appearing or disappearing as separate panels. (developer.apple.com)
Adaptivity and motion
The material’s appearance changes according to its surroundings and functional state. Apple’s demonstrations show adjustments to brightness, shadows, and apparent thickness. For example, a toolbar control expanding into a menu can acquire stronger depth cues and softer light scattering, making the enlarged surface appear more substantial. Motion therefore participates in expressing the relationship between a control and the interface it reveals. (developer.apple.com)
Interface hierarchy and material variants
Apple’s Human Interface Guidelines distinguish Liquid Glass from the standard materials used elsewhere in an interface. Liquid Glass principally occupies a functional layer containing navigation and controls, such as tab bars and sidebars. This layer floats above the content, allowing some of that content to remain visible beneath it. Standard materials instead provide visual separation within the content layer. (developer.apple.com)
This distinction gives the material a structural role rather than treating it as a decorative finish for every surface. Apple’s guidance discourages applying it throughout content backgrounds or indiscriminately to custom controls, because doing so can weaken the separation between content and interaction. Transiently active controls within content, such as sliders and toggles, are an exception. (developer.apple.com)
For custom components, the material has two principal variants:
- Regular: the general-purpose, adaptive variant.
- Clear: a more transparent variant intended for elements over visually rich backgrounds, especially media.
Their appearance can also respond to system preferences, including settings that reduce transparency or increase contrast. They are not simply interchangeable opacity presets. (developer.apple.com)
Developer implementation
Liquid Glass is integrated into Apple’s interface frameworks, including SwiftUI, UIKit, and AppKit. Standard controls and navigation components acquire the updated appearance when applications are built with the relevant software development kits and run on supporting system releases. Adoption therefore does not necessarily require rebuilding an application’s interface from the ground up. (developer.apple.com)
Custom implementations use framework-specific application programming interfaces, including SwiftUI’s glassEffect(_:in:), UIKit’s UIGlassEffect, and AppKit’s NSGlassEffectView. SwiftUI also supports configurable shapes, tinting, and interactive responses. Its default glass effect uses the regular material within a capsule shape behind a view’s content. (developer.apple.com)
Existing custom backgrounds, navigation styling, and animations remain relevant to adoption. Apple’s migration documentation calls for reviewing these customizations and testing different display and accessibility configurations, since standard components adapt automatically but independently implemented effects may not. (developer.apple.com)
Accessibility and technical limitations
Liquid Glass incorporates accommodations associated with digital accessibility. Reduce Transparency, Increase Contrast, and Reduce Motion can modify its visual treatment or animation. These adaptations are part of the system implementation rather than a single fixed presentation of the material. Applications using standard framework components inherit the corresponding behavior, while custom elements require separate testing. (developer.apple.com)
Its transparency and movement also impose design constraints. Apple cautions that excessive glass effects can distract from content and reduce the clarity of the interface hierarchy. The intended result depends on the relationship between foreground controls, underlying imagery, and the material’s adaptive treatment—not on transparency alone. (developer.apple.com)
Rendering cost is another limitation. Apple’s developer documentation states that excessive effect containers, or too many effects applied outside containers, can degrade performance. The number of simultaneous effects and the time spent rendering them therefore matter independently of their visual appearance. (developer.apple.com)
References
- Apple introduces a delightful and elegant new software designapple.com
- Liquid Glass | Apple Developer Documentationdeveloper.apple.com
- Meet Liquid Glass - WWDC25 - Videos - Apple Developerdeveloper.apple.com
- Materials | Apple Developer Documentationdeveloper.apple.com
- Adopting Liquid Glass | Apple Developer Documentationdeveloper.apple.com
- Applying Liquid Glass to custom views | Apple Developer Documentationdeveloper.apple.com