The Definitive Guide to CSS Glassmorphism & Frosted UI
Learn the optical secrets of VisionOS and iOS blur effects, GPU performance optimization, and cross-browser support.
1. The 4 Layers of Realistic Glass
- Translucent Surface: A low-opacity background tint (typically
rgba(255, 255, 255, 0.15)) that allows light to pass through. - Optical Refraction (Blur): The
backdrop-filter: blur(16px)that diffuses background shapes into a silky texture. - Specular Edge Highlight: A 1px border or
inset 0 1px 1pxglow representing reflected light along the top glass edge. - Diffused Ambient Shadow: A broad, low-opacity drop-shadow that elevates the glass sheet away from the backdrop.
2. Browser Compatibility & Safari WebKit
Always specify both backdrop-filter and -webkit-backdrop-filter. Without the vendor prefix, Safari on iOS and macOS will render an opaque or glitchy surface.