What is CSS Border Radius?

The border-radius CSS property allows developers to create beautifully rounded corners, pills, circles, and complex organic blob shapes. It rounds the outer edge of an element's border box, fundamentally transforming harsh structural rectangles into softer, modern UI components.

How to Use the CSS Border Radius Generator

Creating custom shapes is intuitive with our visual editor. Here is a quick guide to getting the most out of the tool:

• Select your unit: Choose between Pixels (px) for rigid UI components or Percentages (%) for responsive blobs and circles.
• Tweak the corners: Use the four standard sliders to adjust the top-left, top-right, bottom-right, and bottom-left radii.
• Enable Advanced Mode: Click the "Enable Advanced (8-Value Blob)" toggle to unlock vertical radii. This allows you to define horizontal and vertical curves independently to create asymmetrical, organic shapes.
• Test Interactions: Toggle the 🖱️ Hover Effect or ✨ CSS Animation buttons to see how your shape behaves dynamically.
• Export: Select your preferred output (Standard CSS, Tailwind, or SCSS) and click "Copy Code", or open it directly in CodePen.

Pro CSS Formatting Tips

Mastering the border-radius property takes a bit of practice. Keep these professional development tips in mind:

• The Pill Trick: To create a perfect pill-shaped button that never distorts regardless of its width, use an excessively large pixel value (e.g., border-radius: 999px;). Do not use 50%, as that creates an oval.
• Responsive Circles: To create a perfect circle, ensure your element has an equal width and height (like aspect-ratio: 1 / 1;) and set the radius to exactly 50%.
• Shorthand Syntax: If your top-left/bottom-right and top-right/bottom-left corners match, you can use just two values (e.g., border-radius: 10px 20px;). If all four match, just use one.
• Clipping Content: Remember that adding a border-radius doesn't automatically hide child elements that bleed over the rounded corners. You will often need to pair it with overflow: hidden; on the parent container.

Standard vs. Advanced Syntax

Most developers are familiar with the basic syntax, which uses 1 to 4 values to set circular radii for the corners.

However, Advanced 8-Value Syntax unlocks massive creative potential. By using a slash (/), you can set independent horizontal and vertical radii for each corner. This is the secret behind organic, liquid-like "Blob" shapes.

Common Uses in Modern Web Design

• Rounded Buttons: A subtle 8px to 12px radius makes buttons feel clickable and friendly.
• UI Cards: Soft corners (e.g., 16px) define the bounds of content blocks gracefully.
• Profile Avatars: Using 50% creates clean circular imagery for user profiles.
• Organic Blobs: By animating 8-value percentages, developers create stunning, morphing background graphics that add depth to hero sections.

Exporting to Tailwind & SCSS

Our generator handles modern frameworks automatically. If you use Tailwind CSS, complex 8-value shapes are generated using arbitrary values (e.g., rounded-[50%_50%...]). If you use SCSS, the tool instantly generates a reusable `@mixin` for your stylesheets.