Glassmorphism CSS Generator

Glassmorphism is a UI style that mimics frosted glass — a translucent surface that blurs whatever sits behind it. It's defined by four properties: a backdrop blur, a low-opacity background tint, slightly boosted saturation, and a thin highlight border. The effect was popularised by Apple in macOS Big Sur (2020) and iOS, and quickly became one of the dominant design trends of the early 2020s. It's most often used on overlays, navigation bars, cards over hero imagery, and floating panels.

Excellent on every modern browser — Chrome, Edge, Firefox, Safari, and the Chromium-based mobile browsers all support `backdrop-filter`. Safari has supported it the longest but still requires the `-webkit-backdrop-filter` prefix, which is why this tool emits both properties. The only place glassmorphism degrades is on very old versions of Firefox (pre-103) — there, the card simply renders with its base background colour, which is a safe fallback.

`backdrop-filter` works by sampling the pixels behind the element and applying a blur — there's nothing to blur if the backdrop is a flat single colour like white or a neutral grey. The glass effect only becomes visible when the backdrop has colour variation: a photograph, a gradient, or layered shapes. That's why every glassmorphism mockup you see online sits over a vibrant gradient or photo. The preview in this tool defaults to a colourful gradient for that reason.

Yes — and they're serious. Translucent surfaces have unpredictable contrast because the colour behind them keeps changing. White text on a glass card looks crisp over a dark photo and disappears over a light one. Before shipping glassmorphism, always test text contrast against the worst-case backdrop and aim for at least WCAG AA (4.5:1 for body text). Many designers add a darker tint behind the glass, raise the background opacity past 0.5, or add a subtle drop shadow to the text to guarantee readability.

Safari — both desktop and iOS — historically required the `-webkit-` prefix for `backdrop-filter`, and many older iPhones and Macs still need it to render the effect correctly. The unprefixed property is the modern standard. Shipping both means the effect works on the widest possible set of browsers without any extra build step or PostCSS plugin. The two values are always identical.

`backdrop-filter` is GPU-heavy because the browser has to re-sample and re-blur the pixels behind the element on every frame. On a small static card it's negligible. On a full-screen overlay that animates, you can see frame drops on mid-range mobile devices. Three rules: avoid glassmorphism on very large elements (>50% of the viewport), don't animate the blur radius itself, and if you must animate, use `will-change: backdrop-filter` cautiously and test on a real phone, not just your laptop.

Tailwind ships utility classes for this: `backdrop-blur-md` (12px blur, roughly the default here), `backdrop-saturate-150`, and arbitrary values like `backdrop-blur-[16px]` if you need a specific size. A typical glass card in Tailwind looks like `class="bg-white/15 backdrop-blur-md backdrop-saturate-150 border border-white/20 rounded-2xl"` — the `/15` shorthand sets background opacity to 15%. Tailwind handles the `-webkit` prefix automatically via autoprefixer in your build.

Small to medium. Glassmorphism works best on cards, toolbars, navigation pills, popovers, and floating action buttons — elements small enough that the user's eye can read both the glass and the content behind it. On large elements (full-bleed overlays, big modals), the blurred backdrop can overwhelm the content and make the page feel laggy. If you need a whole section to feel glassy, use a darker tint and a higher background opacity so the effect reads as a softer surface, not a heavy blur.

On modern iOS Safari, Chrome Android, and Samsung Internet, yes. The performance trade-off is more noticeable on mobile because GPUs are smaller — keep blur values under 20px on full-width cards and avoid stacking multiple glass elements on top of each other. iOS also handles the `-webkit-backdrop-filter` prefix differently across versions, which is exactly why this tool ships both properties — your card looks the same on iOS 14 and iOS 18.

Yes — completely free, no signup, no watermark, no rate limit. Everything runs in your browser. Nothing about your design is sent to a server, logged, or stored — close the tab and it's gone. Bookmark the page if you want to come back.