CSS Minifier

The CSS Minifier compresses your CSS by removing comments, unnecessary whitespace, redundant semicolons and trailing whitespace — producing smaller stylesheets that download faster and parse quicker. It shows the original size, the minified size and the percentage savings live, so you can see exactly how much you are saving.

CSS minification is a standard step in production web builds. A typical stylesheet shrinks by 15–30% after minification, which directly improves page load time — a confirmed Google ranking factor and a real factor in user experience, especially on mobile networks. For sites with large stylesheets (design systems, component libraries, legacy codebases), the savings can be substantial.

This minifier removes: block comments and line comments, leading and trailing whitespace on each line, whitespace around braces and semicolons, the final semicolon before a closing brace, and empty rules. It preserves the semantic meaning of the CSS — selectors, properties, values and important tokens all remain intact. It does not perform aggressive optimizations like shorthand merging or selector deduplication, which can change behavior; the goal is a safe, behavior-preserving size reduction.

For best results, keep your original (un-minified) CSS as your source of truth in version control, and generate the minified version as a build step. Serve the minified version in production and the readable version in development. Everything runs locally in your browser; your CSS is not transmitted or stored.