CSS minification removes everything a browser does not need to render your styles: comments, indentation, line breaks, the space after a colon and the final semicolon in each rule block. Typical savings are 20-30% before compression, and since CSS is a render-blocking resource, that reduction lands directly on First Contentful Paint — one of the metrics Google measures in Core Web Vitals. Selectors, property order and specificity are untouched, so the cascade behaves exactly as before. This is a safe, purely textual transformation you can apply to a hand-written stylesheet, a snippet from a design tool, or CSS extracted from a page you are optimising.
Free, fast, and runs entirely in your browser — no signup, no upload to a server.