What Does the CSS Minifier Do?
The CSS Minifier compresses stylesheets by removing everything a browser doesn't need: comments, line breaks, indentation, spaces around punctuation, trailing semicolons and redundant syntax. It also applies safe micro-optimizations — 0px becomes 0 and six-digit hex colors like #ffffff collapse to #fff. After minifying, the tool reports the exact size reduction, which typically lands between 20% and 40%.
Your rules, selectors and values are never altered — only formatting is stripped — so minified CSS renders pixel-identically to the original.
How to Minify Your CSS
- Paste your stylesheet into the left box.
- Click Minify CSS.
- Check the savings summary, then Copy the result or download it as
style.min.css.
Why Minify CSS?
- Faster page loads — CSS blocks rendering; smaller files mean the browser can paint sooner, improving your Largest Contentful Paint (LCP).
- Core Web Vitals & SEO — page speed is a ranking signal, and every kilobyte of render-blocking CSS counts.
- Bandwidth savings — multiplied by thousands of visitors, a 30% smaller stylesheet is real traffic saved, especially on mobile.
- Best-practice audits — Lighthouse and PageSpeed Insights flag unminified CSS explicitly; this tool clears that audit.
Keep your readable source file for development and serve the minified version in production — the standard workflow even when you don't use a build pipeline.