DesignerMay 28, 2026

CSS Border Radius Generator: Create Rounded Corners Visually

Generate CSS border-radius code with live preview. From simple rounded corners to pill shapes and blobs - no code needed.

# CSS Border Radius Generator: Create Rounded Corners Visually

Rounded corners are one of the simplest and most effective ways to make a design feel modern and approachable. The CSS border-radius property controls how rounded your corners are, but getting the exact shape you want by editing numbers alone is tedious. FreeToolJet's CSS Border Radius Generator lets you design rounded corners visually and copy production-ready CSS in seconds.

Understanding border-radius Syntax

The border-radius property accepts lengths (px, em, %) or percentages. Here's how the syntax maps to actual shapes:

All Four Corners Same

Two-Value Shorthand

Three-Value Shorthand

Four-Value (Individual Corners)

Percentages and the Circle Trick

Use percentages for responsive, proportional rounding that scales naturally with element size.

Preset Shapes

FreeToolJet's CSS Border Radius Generator includes one-click presets for common shapes:

The Pill Shape Explained

/* Input field */ border-radius: 9999px; /* same horizontal and vertical extreme */ `

The 9999px value is a common trick because any very large radius approximates a semicircle — creating that characteristic pill shape regardless of the element's dimensions.

Using Percentages for Responsive Shapes

Percentage-based radius scales with the element's size, making it ideal for responsive designs:

  /* Always stays circular regardless of width/height */
  .avatar {
    border-radius: 50%;

/* Consistent rounding that adapts to container size */ .card { border-radius: 4%; }

/* Asymmetric blob using percentages */ .blob { border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%; } `

Combining border-radius with box-shadow

Rounded corners pair beautifully with shadows. The shadow automatically follows the rounded edge — no extra configuration needed:

  .card {
    border-radius: 16px;
    box-shadow:
      0 4px 12px rgba(0, 0, 0, 0.08),
      0 12px 40px rgba(0, 0, 0, 0.06);
  }

For advanced shadow work, pair with the CSS Box Shadow Generator. And for color-matched effects, use the Color Converter to fine-tune your shadow and background colors.

Common Design Patterns

Subtle Rounded Corners (Cards & Buttons)

Strong Rounding (Badges & Tags)

Pill Buttons

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How to Use the CSS Border Radius Generator

Related Design Tools

Border radius is one part of a complete CSS design toolkit:

FreeToolJet's CSS Border Radius Generator removes the guesswork from rounded corners — design visually, ship CSS instantly.