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CSS Glassmorphism Generator

Tune a transparent glass panel with validated blur, alpha, border, and radius values, then copy production-ready CSS.

Privacy: your files never leave your device. All processing happens locally in your browser.

How to use

  1. 1.Choose a glass color and translucent fill opacity.
  2. 2.Adjust backdrop blur, highlight border opacity, and corner radius.
  3. 3.Inspect the panel over the built-in colored backdrop.
  4. 4.Copy the CSS and test it with a fallback in the real stacking context.

About CSS Glassmorphism Generator

CSS Glassmorphism Generator provides a controlled way to build a translucent panel that reveals and softens content behind it. Choose a glass color, background opacity, backdrop blur, white border opacity, and corner radius. The preview places the panel over a colored background so the backdrop effect is visible, then applies the same computed values used in the copied CSS. This avoids the common mistake of judging blur on a plain background where there is nothing for the browser to filter. The output includes a translucent rgba background, standard backdrop-filter, the WebKit-prefixed fallback used by some browser versions, a one-pixel highlight border, and border-radius.

Glassmorphism depends on transparency. A fully opaque panel can hide the backdrop and make blur appear ineffective even when the property is valid. The opacity control converts a percentage into a stable alpha value, while the selected hexadecimal color is converted into red, green, and blue channels. Border opacity is calculated separately because a subtle light edge often helps distinguish the panel from the material behind it. Blur is serialized as a nonnegative pixel length. Negative blur values are invalid under the filter grammar, so the tool rejects them rather than silently correcting them.

The backdrop-filter property affects pixels painted behind an element, not the element's own children. Backdrop roots created by opacity, filters, masks, clipping, blending, or certain will-change values can limit which background is sampled. Therefore CSS that works in this isolated preview may look different inside a complex stacking context. Test the copied rule in its real parent hierarchy with the actual background image, gradient, or content. If the effect disappears, inspect transparency and backdrop-root boundaries before increasing blur without evidence.

A glass panel is not automatically readable. Busy imagery can remain visible through the blur, and a pale border does not guarantee sufficient separation. Verify text contrast over the full set of backgrounds that users may encounter. Add a solid or more opaque fallback when backdrop filtering is unsupported, disabled, expensive, or overridden by accessibility preferences. Avoid placing long body text over unpredictable imagery. Use padding, sensible maximum width, and a clear focus indicator for interactive content. Transparency should support hierarchy, not obscure it.

Blur can also carry rendering cost, especially over large surfaces, moving video, or nested filtered layers. Keep the filtered area bounded and measure performance on representative mobile hardware. A bigger blur number is not necessarily a better effect. Start around 8–16 pixels and 15–30 percent fill opacity, then adjust against the final backdrop. The generated CSS intentionally omits shadows, padding, positioning, and typography because those belong to the surrounding component system. Add them using existing design tokens rather than turning one panel into a separate visual language.

All calculations run in the browser. Values are not uploaded or saved, no account is required, and no external package is used. The generator validates finite practical ranges and six-digit hexadecimal colors, but it cannot prove browser compatibility, contrast, or rendering performance for your project. Copy the rule, provide a fallback background, test light and dark themes, keyboard focus, forced colors, reduced transparency expectations, responsive sizes, and the exact browsers your audience uses.

Methodology & sources

Validates bounded finite opacity, blur, border-opacity, and radius values; converts a six-digit hex color to rgba; serializes standard and WebKit backdrop blur; and applies the exact generated properties to the preview.

Frequently asked questions

Why is the blur invisible on my page?
The panel needs a transparent background and visible pixels behind it. Backdrop-root boundaries can also limit what is sampled.
Does glassmorphism guarantee readable text?
No. Test contrast over every possible backdrop and provide a more opaque or solid fallback when needed.
Is backdrop blur expensive?
It can be costly over large, moving, or nested areas. Keep the surface bounded and measure on representative mobile devices.

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