The Northern Stars of Liquid Glass
An overview of the new HIG principles of Hierarchy, Harmony, and Consistency
With the release of [your platform here]OS 26, Liquid Glass is officially here. And with it comes a new era under Apple’s new design system. It’s been a fun summer exploring LG alongside the community — especially as each beta changed this, that, and everything in between. But now, with the official release, we can expect things to (mostly) settle into place for a while.
This also means the era of “we’ll wait because they keep changing things” is officially over. Sure, we get a pass for Xcode 26, but starting with Xcode 27+ Liquid Glass becomes the default system in every build.
That makes now the perfect time to understand the three principles at the heart of Liquid Glass. According to Apple’s updated Human Interface Guidelines, they are Hierarchy, Harmony, and Consistency:
While Apple introduces these principles in the HIG and touched on them during the Platforms State of the Union, there’s no single, in-depth guide from Apple that shows how to apply them in practice. So let’s fill that gap — breaking down what each principle means for modern UX and how it translates into real-world SwiftUI.
Hierarchy — The Lighthouse of User Attention
When Apple talks about Hierarchy in Liquid Glass, it’s not about vertical order (top vs. bottom of a screen). It’s about layering — which elements float above your content to guide interaction and which stay embedded in content.
Liquid Glass is optimized for UI elements that sit above the main canvas: navigation bars, tab bars, toolbars, sidebars, and menus. Apple’s new design language turns these controls into translucent, weightless surfaces that make the content beneath feel present and alive — instead of suffocating it.
The result:
Foreground layers = guidance and controls
Background layers = immersive content
Clear, immediate hierarchy for the user’s eyes and fingers
Some examples of how Liquid Glass already aids the hierarchy principle can be found in toolbars and tabview:
We see how core points of interaction, navigation, and functionality do not hinder the main content, but are also elevated into prominence.
How to apply it in SwiftUI:
In many cases (like with toolbars and tabviews), the LG system already sets us up for great hierarchy. But, if we were creating a more custom experience, we should consider the layers of the experience we’re presenting to our users:
VStack(alignment: .leading, spacing: 8) {
Text("Button")
.font(.largeTitle)
Text("...")
.font(.body)
HStack {
Spacer()
Button {
// something
} label: {
Text("Accept")
}
.buttonStyle(.glass)
Spacer()
}
}
.padding()
.background(.green.opacity(0.3))The result when repeating in different button styles shows:
Without glass, the button blends into the (very basic) UI, remaining relatively flat even with the bordered style. But with glass, the button stands out from the content beneath, making it clear that this is a point of interaction and, potentially, state change.
Glass effects already promote hierarchy and naturally produce layering—even on the same literal Z-layer. Think of it as raising user attention to the surface where you need it, instead of piling on more stacks. In Liquid Glass, you don’t fight for hierarchy — you reveal it.
Captain’s Tip: When it comes to hierarchy, think “layers”. The top-most layers (nav bars, toolbars, tab bars) should guide interaction and feel lighter. The bottom layers (content views) should be primary and immersive.
Harmony — Keeping the Currents Smooth
If Hierarchy is about which elements rise to the surface, Harmony ensures those elements move together as one current. It’s not just visual polish — Harmony is spacing, rhythm, and consistency that prevent your layered UI from feeling like a sticker book of floating widgets.
Think of Harmony as composition:
The translucency of glass means elements share visual “DNA” with the content beneath.
Spacing and padding must be tuned so floating elements don’t feel like they’re crashing into each other.
Motion, blur, and tint should echo across layers so the UI feels orchestrated, not random.
One of the best and coolest examples of harmony is in the new backgroundExtensionEffect. We’ve already seen how toolbars and tabviews hover over content. But the extension modifier lets you add context where the system can’t, maintaining visual continuity and harmony.
Harmony also depends on grouping related elements together within clear, recognizable boundaries. In Liquid Glass, this is reinforced through Concentricity—rounded, nested shapes that echo each other—eliminating harsh edges that could feel jarring against content. You can see this in the sidebar from the extension screenshot above. You’ll also find it in the highlighted screenshot of the Maps app below. Notice the way areas of focus are grouped in concentric “containers”, reducing visual noise while reinforcing relationships between actions.
Note: Apple has made it a point that concentric design is so helpful in distinguishing features harmoniously that it’s used throughout Apple hardware design, as well.
How to apply it in SwiftUI:
Much of what keeps harmony is provided for us through many of the components already found in SwiftUI under the new design system. In the following screenshot, concentricity, grouping, spacing, and overlapping (without inteference) is all handled simply by adding components like TabView, tabViewBottomAccessory, and ToolbarItem. Even the rows were given concentricity when applying row spacing:
When you need to introduce harmony where there is more custom/unique UI, there’s help in tools like ConcentricRectangle and backgroundExtensionEffect.
Captain’s Tip: Harmony is your current — it is the tide that quietly carries your users attention from one destination on screen to the next. If one element splashes too loudly, the whole current feels off.
Consistency — Building Trust Across the Voyage
If Hierarchy is about what rises above and Harmony is about how everything moves together, Consistency is about predictability. It’s making sure your UI behaves, looks, and feels familiar — not just across screens, but across Apple’s entire platform fleet.
Consistency isn’t about sameness or stifling creativity. It’s about creating a dependable mental model so users can instantly understand and navigate your experience. In the Liquid Glass era, that extends across:
Apps on the same platform: Shared navigation gestures, familiar placements of toolbars/tabviews, coherent typography.
Across Apple platforms: iOS, iPadOS, macOS, visionOS, watchOS, and tvOS — each with its own scale but unified materials, controls, and motion principles.
Across states of your own app: Light/Dark Mode, compact/expanded, windowed/fullscreen, folded/unfolded devices.
How to apply it in SwiftUI:
By using system components, environment-driven layout, and shared modifiers (rather than reinventing the wheel per screen), maintaining consistency could be as simple as:
var body: some View {
ViewThatFits {
NavigationSplitView {
List(games) { game in
GameRow(game)
}
.listRowSpacing(8)
.navigationTitle("MLB Scores")
} detail: {
GameDetailSheetView()
}
NavigationStack {
List(games) { game in
GameRow(game)
}
.listRowSpacing(8)
.navigationTitle("MLB Scores")
}
}
}Here, we simply rely on ViewThatFits to determine whether we use a SplitView (with a defined detail view) for iPadOS/macOS or a Stack for iOS. Everything else stays the same. This may be a tad over-simplistic, but it highlights how consistency can be achieved with very little. Just look at how the experience changes at various sizes:
Captain’s Tip: Consistency is your compass, letting users sail confidently between your screens and across Apple’s platforms. It isn’t just a guideline — and it doesn’t mean cloning your UI everywhere. It’s about letting users feel at home no matter where they sail. Consistency is the glue holding the entire experience together as windows float, fold, or fade.
Navigating by the Northern Stars
We’ve charted three distinct “stars” of Liquid Glass — Hierarchy, Harmony, and Consistency — but in practice, they’re never separate. They’re constellations, working together to guide your users through a seamless experience.
Hierarchy gives users a clear beacon of interaction. Harmony ensures those interactions flow naturally and feel connected. Consistency builds the trust that lets them navigate confidently across your app and Apple’s platforms.
When you apply all three, you’re not just following Apple’s design principles — you’re creating experiences that feel effortless, resilient, and future-ready.
As Liquid Glass becomes the standard, these principles aren’t checkboxes. They’re habits — ways of thinking about layers, balance, and predictability from the start of your design process. By adopting them now, you’ll spend less time “retro-fitting” later and more time innovating.
Great Article and explanation, Thank you,Danny!