Swiftui Liquid Glass

SwiftUI Liquid Glass

Use native Liquid Glass APIs on iOS 26+. Do not recreate the effect with materials, blurs, or shadows.

Core rules

1. Don't build custom Liquid Glass through adding backgrounds, outlines, blurs and shadows.
2. Buttons — style: use .buttonStyle(.glass) for non-colored buttons, and .buttonStyle(.glassProminent) for tinted buttons. .glassProminent supports .tint(), but this can only be a color (not a gradient).
3. Buttons — shape: use .buttonBorderShape() instead of applying a shape to the button label by hand.
4. Buttons — padding: using this button setup adds roughly 13pt of padding inside the liquid glass shape; keep this in mind when adapting designs.
5. Custom views: use .glassEffect(.regular, in: ...) to embed custom Views inside liquid glass containers.
6. Grouped glass: use GlassEffectContainer when multiple liquid glass elements are next to each other. this View / Container adds a liquid merge effect when the elements grow / touch each other.
7. Scrolling: avoid using liquid glass inside ScrollView and List (anything that scrolls).
8. Bottom bars: when anchoring a liquid glass View to the bottom of the screen, prefer embedding it in .safeAreaBar(.bottom) instead of a VStack or .overlay(). safeAreaBar adds a subtle blur effect behind its content.
9. Toolbar items — no glass: on iOS 26+, navigation bar and window toolbar items get a shared Liquid Glass background by default. For items that should not show the glass capsule (plain icons, custom labels, status text, logos), apply .sharedBackgroundVisibility(.hidden) on the ToolbarItem, not on the inner view.

Decision tree

Need a button?
├─ Neutral / secondary → .buttonStyle(.glass)
└─ Tinted / primary    → .buttonStyle(.glassProminent).tint(someColor)

Need a custom non-button surface (chip, badge, card)?
└─ .glassEffect(.regular, in: shape) on the view content

Multiple glass elements nearby?
└─ Wrap in GlassEffectContainer(spacing: ...) { ... }

Fixed bottom toolbar / action bar?
└─ .safeAreaBar(.bottom) { ... }  — not VStack + overlay

Toolbar item without glass background?
└─ ToolbarItem { ... }.sharedBackgroundVisibility(.hidden)

Inside ScrollView, List, or Form rows?
└─ Do not use Liquid Glass — use solid/material fallback

Workflow

1) Review existing UI

• Flag custom blur/material stacks masquerading as glass.
• Check buttons use .glass / .glassProminent, not hand-built capsules.
• Confirm .buttonBorderShape() is used instead of clipping the label.
• Verify grouped elements sit in GlassEffectContainer.
• Flag glass inside scrollable containers.
• Check bottom-anchored bars use .safeAreaBar(.bottom).
• Check toolbar items that should appear without glass use .sharedBackgroundVisibility(.hidden) on the ToolbarItem.
• Gate with #available(iOS 26, *) and provide fallbacks.

2) Implement or refactor

1. Pick the right primitive (button style vs glassEffect vs safeAreaBar).
2. Apply layout and typography first; add glass modifiers last.
3. Wrap adjacent glass elements in GlassEffectContainer.
4. Account for ~13pt internal button padding when matching designs.
5. Add iOS 26 availability checks and pre-26 fallbacks.

Patterns

Glass buttons

// Secondary / neutral
Button("Cancel") { dismiss() }
    .buttonStyle(.glass)
    .buttonBorderShape(.capsule)

// Primary / tinted — color only, not gradient
Button("Save") { save() }
    .buttonStyle(.glassProminent)
    .tint(.blue)
    .buttonBorderShape(.roundedRectangle(radius: 12))

Do not clip the label yourself:

// ❌ Wrong — shape on label, not the glass button
Button { action() } label: {
    Text("Save")
        .padding()
        .background(.ultraThinMaterial, in: Capsule())
}

// ✅ Right — native glass handles shape and padding
Button("Save") { action() }
    .buttonStyle(.glassProminent)
    .buttonBorderShape(.capsule)

Custom glass surfaces

Label("3 items", systemImage: "tray")
    .padding(.horizontal, 16)
    .padding(.vertical, 10)
    .glassEffect(.regular, in: .capsule)

Add .interactive() when the surface responds to touch:

Text("Tap me")
    .padding()
    .glassEffect(.regular.interactive(), in: .rect(cornerRadius: 16))

Grouped glass (merge effect)

GlassEffectContainer(spacing: 24) {
    HStack(spacing: 24) {
        ToolButton(icon: "pencil")
        ToolButton(icon: "eraser")
        ToolButton(icon: "lasso")
    }
}

private struct ToolButton: View {
    let icon: String
    var body: some View {
        Image(systemName: icon)
            .frame(width: 56, height: 56)
            .font(.title2)
            .glassEffect(.regular, in: .circle)
    }
}

Tune spacing to control how close elements must be before the liquid merge kicks in.

Bottom action bar

ContentView()
    .safeAreaBar(.bottom) {
        HStack {
            Button("Share") { share() }
                .buttonStyle(.glass)
            Button("Done") { done() }
                .buttonStyle(.glassProminent)
        }
    }

Prefer this over pinning with VStack { Spacer(); ... } or .overlay(alignment: .bottom).

Toolbar items without glass

On iOS 26+, toolbar items in the same logical grouping share a Liquid Glass background. Hide it when the item should look bare:

.toolbar {
    ToolbarItem(placement: .principal) {
        Text("Draft")
            .font(.headline)
    }
    .sharedBackgroundVisibility(.hidden)

    ToolbarItem(placement: .topBarTrailing) {
        Button { add() } label: {
            Image(systemName: "plus")
        }
    }
    .sharedBackgroundVisibility(.hidden)

    ToolbarItem(placement: .topBarTrailing) {
        Button("Save") { save() }
            .buttonStyle(.glassProminent)
    }
}

Apply .sharedBackgroundVisibility(.hidden) on the ToolbarItem, not on the Button or label inside. Hiding the effect places the item in its own grouping, which can change spacing relative to glass-backed neighbors.

Do not put the modifier on the inner view:

// ❌ Wrong — modifier on Button, glass background remains
ToolbarItem(placement: .topBarTrailing) {
    Button { add() } label: {
        Image(systemName: "plus")
    }
    .sharedBackgroundVisibility(.hidden)
}

// ✅ Right — modifier on ToolbarItem
ToolbarItem(placement: .topBarTrailing) {
    Button { add() } label: {
        Image(systemName: "plus")
    }
}
.sharedBackgroundVisibility(.hidden)

Availability fallback

if #available(iOS 26, *) {
    content.glassEffect(.regular, in: .rect(cornerRadius: 16))
} else {
    content.background(.ultraThinMaterial, in: RoundedRectangle(cornerRadius: 16))
}

Anti-patterns

| Anti-pattern | Why it fails | Do instead | |---|---|---| | .background(.ultraThinMaterial) + blur + stroke + shadow | Not Liquid Glass; wrong optics and no merge/morph | .glassEffect(...) or button styles | | Gradient .tint() on .glassProminent | API accepts color only | Solid Color tint, or custom label without glassProminent tint | | Glass on List/ScrollView rows | Scroll + glass = visual glitches, perf cost | Opaque/material rows; glass only on fixed chrome | | Shape applied to button label | Misses native padding (~13pt) and border rendering | .buttonBorderShape() | | Bottom bar via .overlay | No system blur bar treatment | .safeAreaBar(.bottom) | | Multiple glass views without container | No merge effect, worse rendering | GlassEffectContainer | | Glass capsule on toolbar items that should be bare | iOS 26 adds shared glass to toolbar groupings by default | .sharedBackgroundVisibility(.hidden) on the ToolbarItem | | .sharedBackgroundVisibility on inner view | Does not remove toolbar glass background | Apply on ToolbarItem (or other ToolbarContent) |

Review checklist

• [ ] No hand-rolled blur/material glass imitations
• [ ] Buttons use .glass or .glassProminent with .buttonBorderShape()
• [ ] Design spacing accounts for ~13pt internal button padding
• [ ] Custom surfaces use .glassEffect(.regular, in: ...)
• [ ] Adjacent glass wrapped in GlassEffectContainer
• [ ] No glass inside scroll views
• [ ] Bottom chrome uses .safeAreaBar(.bottom)
• [ ] Toolbar items without glass use .sharedBackgroundVisibility(.hidden) on ToolbarItem
• [ ] #available(iOS 26, *) with fallback on older OS

Additional resources

• Detailed API notes and morphing transitions: [reference.md](reference.md)
• Applying Liquid Glass to custom views
• Landmarks: Building an app with Liquid Glass

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: FloWritesCode
• Source: FloWritesCode/fwc-swiftui-skills
• License: MIT

Install and usage instructions live in the source repository linked above.