The CSS Minifier is a free online tool that compresses your CSS stylesheet code by removing unnecessary whitespace, comments, line breaks and redundant characters — reducing file size without changing how the CSS behaves in the browser. Smaller CSS files load faster, improving your website's page speed and Core Web Vitals scores.

Page speed is a confirmed Google ranking factor. Even small reductions in CSS file size can meaningfully improve First Contentful Paint (FCP) and Largest Contentful Paint (LCP) times, particularly for mobile users on slower connections.

How to Minify CSS

• Paste your CSS code into the input field
• Click Minify CSS
• Copy the minified output and replace your original CSS file
• Or download the minified version directly

What Gets Removed During Minification

• Whitespace and indentation
• CSS comments (/* ... */)
• Unnecessary semicolons and quotes
• Redundant zeros (e.g. 0.5em becomes .5em)
• Shorthand optimizations

Always keep your original, unminified CSS in version control — only serve the minified version in production. For JavaScript, use our JS Minifier. For HTML compression, try our HTML Compressor. All free, no login needed.

Want to learn more? Read our complete guide: How to Speed Up Your Website and Improve Core Web Vitals →