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Border Radius Generator

Create custom border radius values for all corners. Preview different shapes.

Border Radius

8px
8px
8px
8px
8
8
8
8

Presets

Preview Settings

200px
200px

Preview

Preview
CSScss
.element {
  border-radius: 8px;
}

Border Radius Value

8px

What is a Border Radius Generator?

The Border Radius Generator is an interactive CSS tool that lets you visually control the rounding of element corners using sliders or direct value inputs, then instantly copies the generated code into your project. It supports everything from a simple uniform `border-radius: 10px` to the full eight-value slash syntax for complex asymmetric and organic blob shapes. Developers use it to eliminate manual trial-and-error when crafting buttons, cards, avatars, and decorative shapes.

How to Use This Tool

  1. 1 Set the element dimensions (width and height) in the preview panel to match your real-world use case — use equal values if you need a circle or pill shape.
  2. 2 Adjust the four corner sliders (top-left, top-right, bottom-right, bottom-left) for horizontal radii; toggle the slash syntax mode to independently control vertical radii for elliptical corners.
  3. 3 Watch the live preview update in real time and fine-tune values using direct pixel or percentage inputs for precision — switch to percentage mode for responsive elements.
  4. 4 Copy the generated `border-radius` CSS declaration from the output box and paste it directly into your stylesheet.

Common Use Cases

Buttons and UI Components

Quickly generate uniform or pill-shaped rounding like `border-radius: 8px` or `border-radius: 50px` for buttons, badges, and tags without guessing values manually.

Animated Blob Shapes

Use the eight-value slash syntax (e.g., `50% 40% 30% 60% / 60% 30% 40% 50%`) to create organic fluid shapes for hero section decorations, then animate them with CSS transitions.

Profile Avatars and Image Crops

Set `border-radius: 50%` on a square container to produce a perfect circle crop for user avatars and profile photos in cards or nav bars.

Asymmetric Cards and Modals

Apply independent per-corner values like `border-radius: 10px 40px 40px 10px` to create distinctive asymmetric layouts for modals, progress bars, or featured content blocks.

Tips & Best Practices

  • → Always set an explicit `background-color`, `border`, or `box-shadow` on your element in the preview — rounded corners are invisible on transparent or background-less elements.
  • → Use percentages (`50%`) for circles and responsive components, but switch to pixel values for fixed-size UI elements like buttons where consistent curvature matters regardless of screen size.
  • → When using the slash syntax for vertical radii, remember values before `/` control horizontal radii and values after `/` control vertical — mixing these up is the most common source of unexpected elliptical shapes.
  • → Avoid setting `border-radius` values above 50% on non-square elements; on rectangles this eliminates straight edges entirely and often produces unintended pill distortions on one axis.

Frequently Asked Questions

What is a border radius generator? +

A border radius generator is an online tool that provides a visual interface — sliders, inputs, and a live preview — to build CSS `border-radius` values without writing code by hand. It outputs a ready-to-paste CSS declaration and supports both simple single-value rounding and the full eight-value slash syntax for complex shapes.

How do I use the border radius generator online? +

Open the tool, set your element's dimensions in the preview, then drag the corner sliders or type values to adjust the rounding. Once the preview matches your desired shape, click the copy button to grab the generated CSS and paste it into your stylesheet.

Is this border radius generator free? +

Yes, this tool is completely free to use with no account or login required. You can generate unlimited border radius values, copy the CSS output, and use it in any personal or commercial project.

How do I make a perfect circle with border radius? +

Set your element's width and height to the same value, then apply `border-radius: 50%` — the generator will reflect this in the preview instantly. This works because 50% of each equal dimension meets at the center, creating a circular curve on all four corners.

What is the eight-value slash syntax in border radius? +

The slash syntax (`border-radius: 50% 40% 30% 60% / 60% 30% 40% 50%`) lets you set independent horizontal and vertical radii for each corner — the four values before `/` are horizontal and the four after are vertical. This is what enables asymmetric blob and organic shapes beyond simple rounded rectangles, and the generator's advanced mode provides separate sliders for each set of values.

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