CSS Minifier

Every byte counts when it comes to page load speed – and CSS files are often much larger than they need to be. Development stylesheets are written for humans, with comments, indentation, and generous spacing that browsers simply ignore. Our CSS Minifier strips out everything that isn’t necessary, reducing your stylesheet size and helping your pages load faster, without changing a single line of how your CSS actually works.

CSS Minifier

Paste your CSS below to minify it instantly. Removes comments, whitespace, and redundant characters — all processing happens in your browser.

Original CSS

0 lines

Minified CSS

What Gets Removed

  • ✕ Removed Single-line comments /* … */
  • ✕ Removed Multi-line comments
  • ✕ Removed Newlines, tabs, and extra spaces
  • ✕ Removed Space around { } : ; , > ~ +
  • → Simplified 0px, 0em, 0rem → 0
  • → Simplified 0.5 → .5 (leading zero)
  • → Simplified Last semicolon before }
  • ✔ Preserved All selectors, properties, and values
  • ✔ Preserved String literals and data URIs
  • ✔ Preserved @media, @keyframes, @import rules

Why Choose Our CSS Minifier?

  • Instant in-browser processing – all minification happens locally in your browser. Your CSS is never sent to a server, making this tool completely private and secure.
  • Four configurable options let you choose exactly what gets removed: comments, whitespace, value simplification (0px → 0), and trailing semicolons.
  • Savings dashboard shows original size, minified size, bytes saved, and compression percentage – with an animated progress bar so you can see the impact at a glance.
  • CSS rule count tells you how many rules are in your stylesheet, useful for auditing large or legacy codebases.
  • Copy to clipboard and download as .css file buttons make it easy to use the output immediately, whether you’re pasting it into a theme or saving it as styles.min.css.
  • String and url() protection ensures that content inside quoted strings and data URIs is never corrupted during minification.
  • Supports all CSS, including @media queries, @keyframes, @import, custom properties, and modern selectors.
  • Completely free. No account or login required.

Our CSS Minifier is perfect for:

  • Web developers who want to reduce stylesheet file size before deploying to production without running a full build pipeline.
  • WordPress theme and plugin developers who maintain a readable development stylesheet and need a minified version for production.
  • Designers who write CSS directly and want to quickly compress it before embedding in an email template, landing page, or CMS.
  • Performance-conscious site owners who want to improve Core Web Vitals scores by reducing render-blocking CSS file sizes.
  • Anyone learning CSS who wants to see exactly what whitespace and formatting looks like when stripped from their code.

How to Use Our CSS Minifier:

  1. Paste your CSS into the Original CSS panel on the left. The line count updates automatically as you type.
  2. Choose your minification options using the checkboxes: remove comments, remove whitespace, collapse values, and remove last semicolons are all enabled by default.
  3. Click “Minify CSS” – the minified output appears instantly in the right panel.
  4. Review the Savings Dashboard to see how much size was reduced.
  5. Click “Copy” to copy the minified CSS to your clipboard, or “Download .css” to save it as styles.min.css.
  6. Change any option and the result updates automatically if CSS is already present.

As a general rule, a well-written stylesheet should reduce by 20–40% after minification. If you’re seeing savings below 10%, your CSS may already be fairly compact. If it’s above 60%, there are likely large comment blocks or heavily formatted sections that were taking up significant space.

Frequently Asked Questions

Does minifying CSS change how my website looks?

No. Minification only removes characters that browsers ignore – whitespace, comments, and redundant syntax like trailing semicolons before closing braces. It does not change any selector, property name, or property value, so your website will look and behave identically after minification.

Is my CSS sent to a server when I use this tool?

No. All processing happens entirely in your browser using JavaScript. Your CSS is never transmitted to any server, which makes this tool completely private and suitable for use with proprietary or confidential code.

What does “collapse values” mean?

When this option is enabled, the minifier simplifies numeric values where possible. For example, `0px`, `0em`, and `0rem` are all equivalent to `0` since zero has no unit. Similarly, `0.5` becomes `.5` because the leading zero before a decimal is optional in CSS. These changes reduce character count without changing behaviour.

Can I minify SCSS or LESS with this tool?

This tool is designed for standard CSS. SCSS and LESS are preprocessor languages that contain syntax (like variables, nesting, and mixins) that is not valid CSS. To use this tool, first compile your SCSS or LESS to standard CSS using your preprocessor, then paste the compiled output here for minification.

Should I use the minified or original version in development?

Always use the original, readable version during development. Debugging minified CSS is very difficult because all formatting and comments are removed. Keep the readable version as your source file and use the minified version only for production deployment. Many build tools (webpack, Vite, Gulp) can automate this process, but for simpler projects this tool provides a quick manual alternative.