Glassmorphism CSS Generator

Create frosted-glass UI effects with adjustable blur, transparency, and border.

How to Use Glassmorphism CSS Generator

1

Adjust blur level

Set the backdrop blur intensity for the glass effect.
2

Set transparency

Adjust the background opacity and border settings.
3

Preview the effect

See the glassmorphism effect applied to a sample card.
4

Copy the CSS

Click copy to grab the CSS for your glassmorphism design.

Tested tool guide Tested browser tools Checked August 16, 2026

What Glassmorphism CSS Generator does, with a checked example

A slider-driven generator that turns a handful of settings into a ready-to-paste CSS block for frosted-glass elements: a semi-transparent fill, a backdrop blur that frosts whatever sits behind the element, a hairline border, and a soft shadow. You adjust blur radius, fill transparency, border weight, and corner rounding, and it emits the declarations, WebKit prefix included for Safari. What surprises most users: the frost is only visible when there is something detailed behind the panel. Over a flat background, a glass panel is just a translucent rectangle; the effect lives entirely in what it covers.

Worked example

A concrete input and expected output from the current implementation.

Input

Fill: white at 25% opacity. Blur: 10px. Border: 1px, white at 30% opacity. Corner radius: 12px.

Expected output

.glass {
  background: rgba(255, 255, 255, 0.25);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.30);
  border-radius: 12px;
}

Each opacity percentage is written directly as the alpha channel of an rgba() color (25% becomes 0.25, 30% becomes 0.30), the blur radius is copied into the backdrop-filter value, and the -webkit- prefixed line is emitted alongside for Safari, so every number in the output follows from the settings you entered.

How the result is produced

Sliders to alpha

Each opacity setting is expressed as a percentage and written into the alpha channel of an rgba() color: 25% becomes 0.25. Because the fill and border default to white, the conversion is direct, and the digits in the emitted CSS match the slider positions you set, so the code stays readable and tunable by hand afterward.

Backdrop blur, not element blur

The signature property is backdrop-filter: blur(Npx), which samples what is painted behind the element and softens it, while filter: blur() would soften the element itself. The generator emits the declaration twice, once unprefixed and once with the -webkit- prefix, because Safari and iOS honor only the prefixed form; the semi-transparent fill also keeps the panel visible where backdrop-filter is unsupported.

Good uses

Putting a frosted navigation bar over a scrolling feed of photos or cards, so content slides underneath and stays readable.
Laying a login card or modal over a gradient hero image, pairing the generated class with the site's own colorful backdrop so the glass has something to frost.
Prototyping a glassmorphism look in a mockup and pulling exact, copy-pasteable values to hand to a developer instead of describing the effect in words.

Limits and checks

The frost is invisible over flat or empty backgrounds: backdrop-filter blurs whatever is behind the element, and with nothing detailed there the panel reads as plain translucency. Put a photo, gradient, or busy UI behind it before judging the result.
Browser support is split: Safari and iOS ignore the unprefixed property (the emitted -webkit- line covers them), Firefox has supported unprefixed backdrop-filter since version 103, and older browsers ignore both, leaving a translucent but unblurred panel.
Transparency and blur fight each other: a high-transparency fill with a low blur is nearly invisible, and a dark tint does not obscure what is behind the panel, because only the blur removes detail, not the fill color.

Common questions

Why does my panel look like a plain translucent rectangle?

The backdrop behind it is flat. backdrop-filter only frosts content painted behind the element, so a solid color or empty page leaves no detail to blur. Put a photo, gradient, or busy UI behind the panel and the frosted effect appears. This is the most common misjudgement with this kind of generator.

Does the generated CSS work in every browser?

No. Safari and iOS need the -webkit- prefixed declaration, which the generator includes; Firefox 103 and later support the unprefixed form; and browsers without backdrop-filter support ignore both and show a plain translucent rectangle. The semi-transparent fill keeps the panel usable, but it will not look like glass in older browsers.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.