How to Create the Frosted Glass Effect in CSS (Glassmorphism Generator)

Glassmorphism is the frosted-glass look that took over modern interfaces — translucent panels that blur whatever sits behind them, tinted with a faint color and outlined with a soft, bright border. You have seen it on the macOS Big Sur control center, on Windows 11 Mica surfaces, and across countless dashboards, login cards, and pricing tables. Done well, it adds depth and hierarchy without heavy drop shadows. Done by hand, it is a fiddly stack of CSS properties that are easy to get wrong.

Our free glassmorphism CSS generator turns that fiddly stack into a few sliders. You drag blur, transparency, tint, saturation, border, and radius, watch a live preview render the frosted glass effect over a colorful gradient, and copy production-ready CSS — complete with the -webkit- prefix and a graceful fallback. Everything runs in your browser; nothing is uploaded.

What actually makes glass look like glass

The frosted glass effect is not a single property. It is the interaction of four ingredients, and skipping any one of them is why most hand-written attempts look flat or muddy:

1. The backdrop blur. The hero of glassmorphism is backdrop-filter: blur(...). Unlike a regular filter, which blurs the element itself, backdrop-filter blurs everything painted behind the element. That is what creates the sense that you are looking through frosted glass. A value between 8px and 16px reads as glass; go higher and it becomes opaque fog, go lower and the effect disappears.

2. A semi-transparent fill. The panel needs a background with low alpha — typically a white or light tint at 10–25% opacity. This catches a little light without hiding the blurred content underneath. Pure transparency looks like nothing; full opacity kills the blur.

3. A subtle, brighter border. Real glass edges catch light. A 1px border in the same tint at a slightly higher opacity (around 30–50%) gives the panel a crisp edge and sells the three-dimensionality. Skipping the border is the single most common reason a glass card looks cheap.

4. A soft shadow. A large, low-opacity drop shadow such as 0 8px 32px rgba(0,0,0,0.18) lifts the panel off the background and reinforces that it is floating in front of the content it blurs.

The CSS the generator produces

Set the controls and the tool emits a block you can paste straight into your stylesheet. A typical result looks like this:

background: rgba(255, 255, 255, 0.20); border-radius: 16px; box-shadow: 0 8px 32px 0 rgba(0,0,0,0.18); -webkit-backdrop-filter: blur(12px) saturate(120%); backdrop-filter: blur(12px) saturate(120%); border: 1px solid rgba(255,255,255,0.40);

Notice the saturate(120%) alongside the blur. Bumping saturation slightly makes the colors bleeding through the glass feel richer and more alive — a small touch that separates a polished glass panel from a gray smudge. The generator lets you push it up to 300% or pull it down to a desaturated, steely look.

Why the -webkit- prefix and the fallback matter

Safari — including iOS Safari, which is a huge slice of mobile traffic — still requires the -webkit-backdrop-filter prefix for the effect to render. Ship only the unprefixed property and your glass card will look broken on every iPhone. The generator always outputs both lines, so you do not have to remember.

Just as important is the fallback. A handful of browsers and certain low-power or reduced-transparency modes do not support backdrop-filter at all. Without a fallback, those users see your nearly-transparent panel against the busy background and the text becomes unreadable. The tool wraps a higher-opacity solid background in an @supports not query so that when blur is unsupported, the panel falls back to a legible, more opaque fill. This is the difference between a design that degrades gracefully and one that breaks.

Tips for readable, accessible glass

Glass is beautiful but it fights legibility. Keep these in mind: place glass over imagery or gradients with enough contrast, but never over busy text. Keep body text on glass at a high-contrast color and consider a faint text shadow. Respect users who enable reduced transparency at the OS level — the fallback handles part of this, but test it. And do not stack glass on glass; the blurs compound and the whole thing turns to soup.

Build your frosted glass effect now

Stop copy-pasting half-remembered snippets from old CodePens. Open the Glassmorphism Generator, dial in the blur and tint until the preview looks right, and copy the CSS. It is free, requires no sign-up, and runs entirely in your browser. Pair it with our CSS Gradient Generator to design the background your glass will sit on, and the CSS Box Shadow Generator if you want to fine-tune the lift.