CSS Minifier

Preparing CSS for production

Stylesheets written for humans include indentation, comments and line breaks that make them easy to maintain. Browsers do not need any of that. Minifying removes it, producing a smaller file that downloads faster and is parsed slightly sooner. On sites with large stylesheets, or many visitors on mobile data, the saving is worth having, particularly for CSS that blocks the first render of the page.

This minifier removes whitespace and ordinary comments while leaving the meaning of your CSS unchanged. Strings and url() values are kept exactly as written, so font names, content values and image paths are not damaged. Comments that start with /*! are kept, because they usually contain licence notices that must stay with the code. The tool does not rename classes or merge rules, which keeps it predictable and safe to use on any stylesheet.

Keep your original, readable CSS as the version you edit and use the minified copy only for publishing. If something looks different after minifying, the original CSS probably contained a syntax error that the browser was quietly ignoring, so check it with the beautifier. For bigger improvements, remove rules you no longer use, combine small files to reduce requests, and make sure your server sends CSS with compression enabled. Critical styles needed for the first screen can also be inlined in the page head, with the rest loaded normally. Everything runs locally in your browser, so private projects and client work are never uploaded. Checking the page on a phone and a desktop after publishing confirms that every style still applies as intended, especially for menus and forms.