Why Minify CSS?
CSS minification removes unnecessary characters — whitespace, comments, newlines, and optional semicolons — from your stylesheets without changing their functionality. A typical stylesheet shrinks by 30% to 60% after minification, which directly reduces download size and improves First Contentful Paint and LCP. Smaller CSS also means fewer bytes for the parser to process, which is especially important on mobile networks. Because minified CSS is functionally identical, it is a safe, high-impact optimization you can apply with a single tool.
What Minification Removes
Minifiers strip all comments, collapse runs of whitespace, remove unnecessary semicolons and line breaks, and shorten colors where safe, such as converting #ffffff to #fff. Advanced minifiers also merge duplicate selectors and properties, remove unused rules when used with purge tooling, and compress shorthand properties. The result is a compact file that produces the exact same layout and styling as the original. It is best practice to keep your human-readable source in your repository and only deploy the minified artifact.