CSS Border Radius Generator

How to use CSS Border Radius Generator

1. Open CSS Border Radius Generator — it runs entirely in your browser with no setup.
2. Paste or type your input into the text area, or upload a file where supported.
3. Set any options you need. The result appears in the output panel — there is no upload step and no waiting on a server.
4. Review the output instantly; large inputs are handled locally without lag.
5. Copy the result to your clipboard or download it. Your data never leaves the page.

Why use CSS Border Radius Generator?

• 100% free with no limits, no sign-up and no watermarks.
• Private by design — your data are processed in your browser and never uploaded to a server.
• Fast and lightweight, with instant results even on a phone or a slow connection.
• Works everywhere — any modern browser on Windows, macOS, Linux, Android or iOS.
• Part of a full developer tools suite, so related border radius tasks are one click away.

What people use CSS Border Radius Generator for

• Designing an asymmetric card or button shape without guessing values.
• Producing an organic blob shape for a background element.
• Matching a rounded corner from a design file precisely.

CSS Border Radius Generator: limits and things worth knowing

• The slash syntax sets elliptical corners: the values before the slash are horizontal radii and those after are vertical. That is what produces the soft blob shapes a single value cannot.
• Percentages are relative to the element's own width and height, so a percentage radius reshapes as the element resizes while a pixel radius does not.
• If the radii on one edge add up to more than that edge's length, the browser scales them all down proportionally rather than overlapping them.
• border-radius clips the background and the border but does not clip overflowing children unless you also set overflow: hidden.

Is it private and secure?

Your privacy is built in. CSS Border Radius Generator runs completely on your device, so whatever you enter stays in your browser and is never transmitted, logged or stored on any server.

Network activity: none. Nothing is sent and nothing is fetched. This tool makes no network request at all once the page has loaded — which is why it keeps working if your connection drops.

You do not have to take that on trust — our privacy proof page publishes the Content-Security-Policy that enforces it, lists every third party it permits, and shows how to verify the whole claim yourself.

Learn more

Is It Safe to Paste Production Data Into Online Tools? — JWTs, API responses and env files get pasted into online formatters every day. Here's what actually happens to that data and how to check before you paste.