What is Glassmorphism?

Glassmorphism is a modern UI design trend characterized by a frosted-glass effect. By creating a semi-transparent, blurred background behind an element, designers can establish a clear visual hierarchy and a sense of depth, making elements appear as if they are floating in 3D space over a colorful background. This aesthetic was heavily popularized by Apple in iOS and macOS Big Sur, and later adopted by Microsoft in Windows 11.

How the CSS Backdrop-Filter Works

The magic behind Glassmorphism is entirely powered by a single CSS property: backdrop-filter. Unlike the standard filter property (which blurs the element itself), backdrop-filter: blur(10px) applies the blur exclusively to the area behind the element. To make this work, the element must have a slightly transparent background color, typically achieved using an RGBA value like rgba(255, 255, 255, 0.1).

Accessibility and Best Practices

While Glassmorphism looks incredibly sleek, it can present severe accessibility issues if implemented poorly. Because the background is semi-transparent, the contrast ratio of the text sitting on top of the glass can fluctuate depending on what is behind it. Always ensure that you use high-contrast text (pure white or dark gray) and add a subtle 1px border to the glass element to clearly define its edges for visually impaired users.