CSS Minifier & Beautifier

How to Use the CSS Minifier

1. Paste your CSS into the input area on the left (or top on mobile).
2. Choose a mode — Minify (default) compresses your CSS, Beautify formats it with consistent indentation.
3. View the result instantly in the output panel on the right.
4. Copy or download — use the buttons above the output to copy to clipboard or save as output.css.

What This CSS Minifier Does

This free online CSS minifier compresses your stylesheets by removing everything that the browser does not need to render your page correctly. It strips comments, collapses whitespace, removes unnecessary newlines, and eliminates redundant characters around selectors and properties. The result is a smaller CSS file that loads faster — sometimes significantly so.

Minification Features

• Comment removal — strips all /* ... */ block comments
• Whitespace collapse — replaces multiple spaces and tabs with single spaces where needed
• Newline removal — collapses the stylesheet to the minimum number of lines
• Selector compaction — removes spaces around :, ;, ,, }, +, ~, >
• Trailing semicolons — removes the last semicolon before each closing brace

Beautify Features

• Consistent indentation — choose 2-space or 4-space indentation for nested rules
• Newlines after declarations — each property/value pair gets its own line
• Space after colon — ensures color: red rather than color:red
• Space before opening brace — formats selector { consistently

Why Minify CSS?

Every kilobyte you shave from your CSS is one less kilobyte the browser has to download, parse, and apply before rendering the page. For users on slow mobile connections, this matters enormously. Google's Core Web Vitals metrics — particularly Largest Contentful Paint (LCP) and First Contentful Paint (FCP) — are directly influenced by how quickly render-blocking resources like CSS can be processed. Even a 30% reduction in CSS file size can measurably improve page load times and search ranking.

Production websites should always serve minified CSS. Tools like webpack, Vite, Parcel, and esbuild minify CSS automatically as part of their build process. If you are working on a project without a build tool — or if you need to quickly minify a single file — this browser-based tool is the fastest option. No installation, no account, no upload.

CSS Minification vs. Gzip

Minification and server compression are complementary, not competing strategies. Gzip and Brotli compression are applied by the web server when sending files to the browser. They work by finding repeated patterns in the file and encoding them more efficiently. Minification reduces the source size before compression is applied. The two strategies together produce the smallest possible transfer size. A minified CSS file that is also gzip-compressed on the server can be 70-90% smaller than the original unminified, uncompressed file.

When to Beautify CSS

CSS beautification (also called pretty-printing or formatting) is useful when you receive minified CSS from a build tool or external stylesheet and need to read or debug it. Minified CSS is intentionally difficult for humans to read — property declarations, selectors, and values are all run together on a single line. The beautify mode adds consistent indentation and line breaks, making the structure of your CSS clear at a glance. This is especially useful when reviewing third-party libraries, debugging specificity issues, or learning from existing codebases.

Related Tools

After minifying your CSS, you may also want to minify your JavaScript with our JS Minifier, or compress your HTML with our HTML Minifier. For formatting other data formats, try the JSON Formatter or XML Formatter.