CSS Border Radius Generator is designed for the exact search intent behind “css border radius generator”. Generate CSS border-radius values for uniform or per-corner rounded corners and copy the resulting declaration. Generate CSS border-radius values for uniform or per-corner rounded corners and copy the resulting declaration. Basic syntax border-radius can take one to four radius values to control the element's corners. Per-corner values Four values map clockwise from top-left: top-left, top-right, bottom-right, bottom-left . Elliptical radii CSS also supports horizontal and vertical radii separated by / , allowing elliptical rather than purely circular corners. Worked example: border-radius: 12px 24px 12px 24px; alternates the corner radii clockwise. Common practical uses include Design cards and buttons; Prototype asymmetric corners; Generate CSS for UI components; Test rounded visual treatments. Important limitations: Very large radii can be constrained by the box geometry. Browser rendering follows CSS radius-overlap rules. The generator should only promise elliptical controls if the interface exposes them. Key questions this page should answer include: What does border-radius do? It rounds the corners of an element's border box. What do four border-radius values mean? Top-left, top-right, bottom-right and bottom-left, in that order. Can border-radius use percentages? Yes. Can CSS create elliptical corners? Yes, with horizontal and vertical radii separated by a slash. Does a large radius always create a perfect circle? No. The result depends on the element's width, height and radius values. The page should stay focused on this differentiator: Target copy-ready CSS plus per-corner and elliptical-radius behavior instead of a shallow visual-only page. The tool should appear before the explanatory copy so a visitor can complete the task immediately, then use the supporting content to verify the method and understand the result. The explanation should keep terminology consistent with the calculator or converter interface, because a mismatch between labels in the tool and labels in the content can create confusion and weaken search-intent alignment. Where the calculation or transformation has edge cases, the page should state them directly instead of implying that every input is valid.
How to use this tool
Basic syntax
border-radius can take one to four radius values to control the element's corners.
Per-corner values
Four values map clockwise from top-left: top-left, top-right, bottom-right, bottom-left.
Elliptical radii
CSS also supports horizontal and vertical radii separated by /, allowing elliptical rather than purely circular corners.
Examples
Four corners
<code>border-radius: 12px 24px 12px 24px;</code> alternates the corner radii clockwise.
Common use cases
- Design cards and buttons
- Prototype asymmetric corners
- Generate CSS for UI components
- Test rounded visual treatments
Frequently asked questions
What does border-radius do?
It rounds the corners of an element's border box.
What do four border-radius values mean?
Top-left, top-right, bottom-right and bottom-left, in that order.
Can border-radius use percentages?
Yes.
Can CSS create elliptical corners?
Yes, with horizontal and vertical radii separated by a slash.
Does a large radius always create a perfect circle?
No. The result depends on the element's width, height and radius values.