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About this tool
Create premium glassmorphic UI cards visually. Customize blur, background opacity, border styling, and shadows with clean CSS output.
The Glassmorphism CSS Generator builds a frosted-glass card rule — background rgba, border-radius, box-shadow, backdrop-filter: blur() and a 1px translucent border — from five sliders and two colour pickers, and shows the result live over a dark scene with coloured blobs behind it. Backdrop blur runs from 0 to 40px, corner radius from 0 to 50px, and background, border and shadow opacity are each set as a percentage that is converted into the rgba alpha channel. It is for designers and front-end developers who want to tune the frosted look by eye and leave with the exact CSS rather than guessing alpha values in devtools.
Open Glassmorphism CSS Generator on AltFTool — it loads instantly in your browser.
Under Glass Card Customization, drag Backdrop Blur (0-40px), Border Radius (0-50px), Background Opacity, Border Opacity and Shadow Density, and set Card Color and Border Color with the two pickers — or start from the Frosty White, Deep Charcoal, Neon Cyan or Ultra Clean preset.
Watch Live Preview, where the card sits over blurred pink, cyan and orange blobs on a near-black stage, and keep adjusting until the text stays readable.
Generated CSS Code shows the six declarations — background rgba, border-radius, box-shadow 0 4px 30px, backdrop-filter, -webkit-backdrop-filter and a 1px border; Copy takes the rule body and Download saves glassmorphism-card.css wrapped in a .glass-card selector.
The live card sits above blurred gradient blobs on a near-black stage, which is where a glass effect actually succeeds or fails — a flat swatch hides the problem.
You move a 0-100% slider and the tool converts your hex colour into the matching rgba() value, so you never hand-calculate an alpha or mismatch the border and background tints.
Frosty White, Deep Charcoal, Neon Cyan and Ultra Clean presets set blur, colours and opacities together, so you begin from a coherent look and adjust from there.
Six declarations: background as an rgba value, border-radius in px, box-shadow set to 0 4px 30px with your chosen black alpha, backdrop-filter: blur() with the -webkit- prefixed twin, and border: 1px solid with the border rgba. The download wraps them in a .glass-card selector and saves glassmorphism-card.css.
Most glassmorphic UI lands between roughly 8px and 20px of backdrop blur; the slider covers 0 to 40px so you can push further for a heavy frosted panel. Higher blur lets you drop background opacity while keeping foreground text legible, which is usually the trade-off you are tuning.
It is supported across current Chrome, Edge, Safari and Firefox, and the generated rule also emits -webkit-backdrop-filter for older WebKit builds. Where it is unsupported the card falls back to a plain translucent background, so pick a background opacity that still reads acceptably on its own.
Usually because background opacity is too high or the content behind it is high-contrast. Try lowering background opacity toward 10-20%, raising the blur, and keeping the border alpha near 25-30% — the border is what gives the panel its edge once the fill is nearly transparent.