Apple sought a new design language to unify the look and feel of interface elements across its devices, with their various window sizes and displays.[2][3] The company decided to move away from the flat design cues popularized by Jony Ive in iOS 7 (2013) toward more expressive, skeuomorphic elements.[4][5] It also decided to introduce a dynamic "material", a visual effect that provides a sense of depth and hierarchy between elements.
The "material" of Liquid Glass combines the "optical properties of glass with a sense of fluidity".[6] It has translucent elements that adapt to their environment, refracting and reflecting elements placed behind them. Lighting and shaders are used to suggest clear or frosted glass; elements adapt to a light or dark appearance to make text and icons on top of the material legible.[7][8][9][10] On iOS and iPadOS, elements react to the device's movement with animations that suggest the movement of a drop of liquid.[11]
Apple's updated human interface guidelines say that apps made with Liquid Glass should show hierarchy between content and controls.[12]
Implementation
Liquid Glass overhauls existing iOS interface components such as text, sliders, toggles, alerts, panels, sidebars. The material is integrated into various apps and system features such as the Dock, notifications, and Control Center; it can also be used by third-party apps.[10][13]
App icons have been redesigned to use a layered system akin to the one used on visionOS and tvOS, applying translucency and a glass-like shimmer effect, which also reacts to device movement, while applying greater use of gradients. App icons can adopt a clear appearance that make them look transparent.[14] Toolbars and other elements on-screen are no longer pinned to the device's bezels, but are separated into bubbles that appear and disappear based on the context. For example, the Music app's tab bar shrinks when scrolling. The new design also allows the material to change its shape and size, such as the text selection tooltip expanding to show all options in a vertical list.[15]
Apple's senior vice president of software engineering, Craig Federighi, said designers used the company's industrial design studios to fabricate glass of various opacities and lensing properties, so they could closely match the interface properties to those of real glass.[8] He also said Apple silicon provides the extra computational power required to run Liquid Glass.[16][17]
Liquid Glass has received a generally mixed response. Some reviewers praised its ability to emulate the refractive and lensing qualities of real glass, highlighting the visual sophistication of the design.[24][4][20]
At the same time, critics described the interface as distracting and, in some cases, less usable. Designers interviewed by Wired noted that the visual effects could draw attention away from app content, while also raising concerns that smaller development teams might struggle to meet the increased design complexity.[4]
Some commentators argued that Liquid Glass departs from established user interface conventions in ways that may make macOS more difficult to navigate.[25][26]
Legibility has been a recurring concern. Some designers reported that the level of transparency in certain elements made text harder to read,[4] particularly in low-contrast conditions such as direct sunlight.[24][27]
Following feedback from the first developer beta, Apple made several adjustments to improve readability. These included increasing opacity in navigation bars and interface chrome, refining system overlays and modal backgrounds, and introducing additional user controls for transparency in later builds.[28][29][30]
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