Glassmorphism creates a frosted glass UI effect — semi-transparent panels with blurred backgrounds behind them. Use our free Glassmorphism CSS Generator to export pure CSS, Tailwind classes, or CSS variables with live preview. Part of our Complete Developer Tools Guide.
What Is Glassmorphism?
A UI design trend popularized by Apple macOS Big Sur and Microsoft Fluent UI — frosted glass panels that let background content show through with a blur effect. Works well for cards, modals, navigation bars, and overlays.
The CSS Behind Glassmorphism
The core stack: backdrop-filter: blur() + semi-transparent background: rgba() + subtle border + box-shadow. The blur applies to everything rendered behind the element, creating the frosted appearance.
The -webkit- Prefix
Safari still requires -webkit-backdrop-filter alongside backdrop-filter for full compatibility. Always include both in production CSS.
Firefox and Glassmorphism
Firefox has limited backdrop-filter support — disabled by default. Use an @supports not (backdrop-filter: blur(1px)) fallback with a higher-opacity background so content remains readable. Our generator includes this fallback automatically.
Performance Considerations
Each glass element triggers a separate GPU blur pass. Limit to 3–5 elements per page. Never animate blur values — it causes severe jank on mobile. Use glassmorphism on key UI elements only, not every card on the page.
When to Use Glassmorphism
Best for: navigation bars, modal overlays, floating cards on colorful backgrounds, and hero sections. Avoid: dense data tables, long-form text blocks, and pages where readability is critical over aesthetics.
Tailwind CSS Glassmorphism
Tailwind provides backdrop-blur-md, bg-white/20, rounded-2xl, and backdrop-saturate-150. Custom blur values need arbitrary syntax: [backdrop-filter:blur(12px)]. Our generator outputs all three formats — CSS, Tailwind, and CSS variables.
Frequently Asked Questions
What CSS property creates the glassmorphism effect?
The glassmorphism effect is primarily created by backdrop-filter: blur() combined with a semi-transparent background (rgba). The blur applies to everything behind the element, creating a frosted glass appearance. You also need a subtle border and box-shadow to give the element definition.
Does glassmorphism work in Firefox?
As of 2026, Firefox has limited backdrop-filter support — it's disabled by default and requires users to enable a flag in about:config. Always implement a fallback using @supports: if backdrop-filter isn't supported, show a higher-opacity background so text remains readable without the blur effect.
How do I add glassmorphism in Tailwind CSS?
Use Tailwind's backdrop utilities: backdrop-blur-md for blur, bg-white/20 for 20% opacity background, and rounded-2xl for border radius. Some custom blur values may require arbitrary syntax like [backdrop-filter:blur(16px)]. The pure CSS approach gives you more precise control.
Is glassmorphism bad for performance?
backdrop-filter is GPU-intensive because each glass element requires a separate blur calculation on the GPU. Using 3-5 glass elements on a page is generally fine. Using 10+ glass elements, or animating the blur value, can cause performance issues especially on mobile. Use sparingly on key UI elements only.