Border Radius Generator
Border Radius Generator. Free, no signup, no watermark. Runs in your browser — your file never leaves your device.
How to border radius generator
- Add your input — Paste or type into the box above. There is no length limit, because the work happens on your own machine rather than in a request to a server.
- Adjust the options — Where the tool offers settings, change them and the output updates immediately — there is nothing to submit.
- Copy the result — Use the copy button, or select the output and copy it by hand. Nothing is stored once you leave the page.
What this tool does
To use the border radius generator, enter a colour in any common CSS notation above. The converted values appear immediately, along with the WCAG contrast ratio against black and white. The tool is free, needs no account, applies no watermark, and has no daily limit.
What this tool does
Colour conversion is arithmetic, so any tool will get the numbers right. What most of them omit is the part you actually needed: whether text will be readable on the colour you just picked. Every result here reports the WCAG contrast ratio against black and white, and names which one to use.
Why nothing is uploaded
This tool runs entirely on your own device. Your file is read into memory by JavaScript on this page, processed there, and handed back to you as a download. It is never transmitted to us, which means there is nothing on our side to store, log, leak or forget to delete.
You can verify that yourself: load this page, disconnect from the internet, and the tool still works. That is a different claim from a privacy policy promising prompt deletion, and it is the reason this site exists.
Contrast, not just conversion
The conversions themselves are arithmetic, and any tool gets them right. What most omit is the part you probably needed: whether text will actually be readable on the colour you have chosen.
Every result reports the WCAG contrast ratio against both black and white, and names which to use. The thresholds are 4.5:1 for body text at AA, 3:1 for large text, and 7:1 for AAA. Those are not stylistic preferences — they are the line between text most people can read comfortably and text a substantial minority cannot.
The ratio is computed from relative luminance with each sRGB channel linearised first, as the specification requires. Averaging the raw channel values instead — which several online tools do — produces a number that can be badly wrong for saturated colours, and wrong in the flattering direction.
What it costs
Nothing. There is no account, no email capture, no free-trial countdown, no watermark on the output and no daily limit. The site is funded by advertising, which sits below the tool and never between an input and its result.
Works offline
Because everything runs locally, this tool keeps working once the page has loaded even if your connection drops. That is worth knowing on a train, on conference WiFi, or anywhere the network is unreliable — and it is the clearest demonstration that your file really is not going anywhere.