Custom Window Background Demo

A showcase of different window background styles and visual effects available in macOS using NSVisualEffectView and NSGlassEffectView. Features dynamic switching between different background materials with optional tint colors.

No private APIs are used.

To test these out, clone this repo and open in Xcode, then run the project. You can switch between different background styles using the dropdown menu in the app.

Most of the code is in BackgroundViewController.swift.

Liquid Glass Effects

Note

Images are available in light and dark themes, switch the browser/system dark mode to see them.

Liquid Glass is introduced in macOS 26, which is available through NSGlassEffectView.

Regular Glass

A regular glass effect that provides a frosted glass effect with a slight background blur and distortion on the edges.

let view = NSGlassEffectView()
view.cornerRadius = 16
view.style = .regular

Clear Glass

A clear variant of the glass effect that provides a transparent background without any blur.

let view = NSGlassEffectView()
view.cornerRadius = 16
view.style = .clear

Glass with Tint Color

Glass effect with custom tint color applied.

let view = NSGlassEffectView()
view.cornerRadius = 16
view.style = .regular
view.tintColor = NSColor(tintColor)

Other Background Styles

These styles use NSVisualEffectView with different materials and blending modes to create various background effects.

HUD Window

let view = NSVisualEffectView()
view.material = .hudWindow
view.blendingMode = .behindWindow
view.state = .active

Popover

let view = NSVisualEffectView()
view.material = .popover
view.blendingMode = .behindWindow
view.state = .active

Menu

let view = NSVisualEffectView()
view.material = .menu
view.blendingMode = .behindWindow
view.state = .active

Under Window Background

let view = NSVisualEffectView()
view.material = .underWindowBackground
view.blendingMode = .behindWindow
view.state = .active

Titlebar

let view = NSVisualEffectView()
view.material = .titlebar
view.blendingMode = .behindWindow
view.state = .active

Requirements

• macOS 26.0
• Xcode 26.0 Beta 5