WWDC: What we know so far about Apple’s Liquid Glass UI

At WWDC 2025, Apple changed how we interact with our devices with the introduction of a new user interface it calls Liquid Glass. Apple CEO Tim Cook described it this way: “Expressive. Delightful. But still instantly familiar.”

First appearances matter, and what Apple has tried to achieve with Liquid Glass is to bring together the optical quality of glass and the fluidity of liquid to emphasize transparency and lighting when using your devices. It’s a move away from the flat UI we’ve become accustomed to and is supported by tweaks across the operating systems. That means elements that were rectangular, such as tool bars in apps, have been redesigned with rounded corners.

Apple is also maximizing content displayed on-screen through translucent tool bars with groups of dynamic controls to allow for easier navigation across apps.

Apple’s design teams were given rare permission to break cover following the introduction. One Apple Human Interface designer explained that the work was the product of an army of designers and engineers, explaining: “We’re designing it to bend and shape light while feeling like an elastic, flexible material that can dynamically shape shift, to make apps feel fluid and organic.”

What people are saying about Liquid Glass

While reality-distorting Apple critics seem to want to compare Apple’s design to Microsoft Vista’s failed attempt to emulate Mac OS X’s Aqua interface, more serious insight is emerging from across the industry, with the consensus quite positive. 

Anastasiia Satarenko, senior design researcher at technological R&D center MacPaw, told me: “The ‘Liquid Glass’ concept combines fluidity and dynamic motion to present a subtle beauty that mimics water; when static, it may be a bit unassuming, but it really shines when it’s in motion.”

Satarenko also noted: “They’re working to build off of the Vision Pro/visionOS and incorporate it into all their products to finally reconnect the user interface again. This decision makes total sense, and it was just a matter of time before they implemented it. Also, this update makes it simpler to incorporate any apps into the Vision Pro, as the software will already be designed for it.”

Morgan Stanley analyst Erik Woodring put it this way in a statement to Computerworld: “Apple’s broad OS redesign across platforms simplifies the UI and makes for a more unified experience…, which enhances the ecosystem experience. Overall, these enhancements remind us of old WWDC’s and highlight Apple’s innate attention to detail.”

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Despite the plaudits, there have been criticisms around readability, particularly when the UI is set to its most translucent mode.

“It’s hard to read sometimes,” said designer Allan Yu, “I think because they’ve set it to be a little too transparent.” Apple will almost certainly address these criticisms before it arrives in final form on various operating systems. (It’s currently only available in early developer betas.) To my eyes, Liquid Glass is a particular problem in Control Center; Apple may need to make everything underneath the controls more opaque.

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So just what is Liquid Glass?

It is important to stress that Liquid Glass will be deployed across all Apple devices, from Macs, iPhones, and iPads, to Apple TV and even Apple Watch. In use, the new interface elements are both translucent and dynamic, giving you the impression that your device is made of liquid, not metal and glass. It delivers a graphics-rich environment made possible by the power of Apple Silicon, which has the power to run it.

Like glass, you’ll find the color of interface elements is informed by the content it surrounds or sits above. Apple calls some of this “lensing” — the ability to dynamically bend and shape light to reflect what you’re working with. “Liquid Glass objects materialize in and out by gradually modulating the light bending and lensing, ensuring a graceful transition that preserves the optical integrity of the material,” Apple said in a statement.

You’ll see interesting specular highlights and on-screen physics in action; some elements seem to bounce, others like to reflect light, and all these interactions are rendered in real time.

The new UI also makes demands of the elements used most — buttons, switches, text, media controls, as well as tab bars and sidebars — all have been tweaked for the new design paradigm. In part, this means all those elements become concentric, with the rounded corners of Apple’s hardware and app windows.

Controls are somewhat nested; they sit on a functional layer above the apps and morph into other controls as you seek them. They are also grouped within the interface; in one example, the Apple Music volume slider pops up above the content browser.

Also, when you scroll, you’ll find tab bars and sidebars work differently; tab bars shrink so they get out of the way of the content, while sidebars have been designed to feel more contextual to the content you’re viewing.

To get a sense of how this all fits together, Apple took pains to show how the time clock now fluidly adapts itself to fit behind the subject of a photo if you use an image as a wallpaper on your iPhone’s Home screen. Apple has done detailed work here — even the San Francisco typeface now dynamically scales the weight, height, and width of each character to fit the scene.

What about developers?

As you’d expect, Apple put together extensive information to help developers deploy Liquid Glass in their apps and created new APIs for use in SwiftUI, UIKit and AppKit. And while some developers will likely lag behind as they always do, most will be able to relatively easily refresh the design of their apps for the new UI.

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One new tool is Icon Composer, a tool with which to create Liquid Glass icons that render in the different looks the UI supports – light, dark, tinted, and clear.

Making sure apps properly support the subtle nesting within the new UI is a task in itself. Apple’s guidelines advise developers to think about a clear hierarchy of interface elements in order to make it easy for users to get to the element they require. Apple is also pushing developers to craft their apps to better reflect the rounded corners on its hardware and software and to rigorously adhere to the new platform conventions.

While it will take time for Apple users and developers to become fully accustomed to using Liquid Glass, the interface is quite beautiful, and lends itself for use across all manner of hardware and software devices. That makes it an appropriate change as Apple prepares for another decade of product design.

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