Minify and compress CSS code to reduce file size, improve page load speed, and boost Google Core Web Vitals scores. All processing happens in your browser.
Remove whitespace, comments and empty rules from CSS files
Typically reduces CSS by 20–40% for faster page loads
Strips all /* */ comments while keeping code functionality
All selectors, properties and values remain intact
Original vs minified size shown with compression percentage
Copy minified CSS to clipboard for immediate use
Paste your CSS stylesheet code into the input area.
Hit Minify CSS to compress and strip whitespace and comments.
Check the size reduction percentage in the statistics panel.
Copy minified CSS and use it in your production site.
CSS files are render-blocking resources — browsers cannot display page content until all CSS is fully downloaded and parsed. Every extra kilobyte in your stylesheets adds time before the first content appears on screen. This is why Google's PageSpeed Insights and Core Web Vitals scores are so sensitive to CSS file size.
For the average website, CSS accounts for 60-120KB of page weight. Minifying this to 40-80KB (and then GZIP compressing it to 10-20KB) creates a measurable improvement in Largest Contentful Paint (LCP) — often the difference between a "Good" and "Needs Improvement" Core Web Vitals score. Better scores mean better SEO and better user experience on slow mobile connections.
This free CSS minifier handles all standard minification transformations: removing comments, collapsing whitespace, stripping trailing semicolons, and optionally removing zero units. Paste your CSS, click Minify, and copy or download the compressed output.
On average, CSS minification reduces file sizes by 20-40%. Combined with GZIP server compression, total savings reach 70-80%.
BEFORE (readable)
AFTER (minified)
CSS minification removes all unnecessary characters without changing visual behavior: comments, extra whitespace, line breaks, trailing semicolons, and redundant unit definitions (0px → 0). Browsers parse minified and unminified CSS identically — the only difference is download speed.
Typically 20-40%. A well-commented 100KB CSS file can become 60-80KB after minification, then 15-25KB after GZIP compression — an 80%+ reduction. The actual savings depend on how heavily commented and indented the original CSS is.
No. Whitespace, line breaks, and comments have no visual impact. Browsers parse minified and formatted CSS identically. The "Remove zero units" option (0px → 0) is also semantically identical — CSS treats 0 and 0px as the same value for all properties.
No — develop with readable, formatted CSS and only minify for production. Set up your build process (Webpack, Vite, Sass CLI) to automatically minify CSS on production builds. This tool is ideal for manual minification or quick checks on specific stylesheets.
Minification removes unnecessary characters from the source file itself — the file is physically smaller on disk. GZIP/Brotli compression is applied by the web server at the HTTP level and decompressed automatically by browsers. Both work together: minify first, then the server compresses the transfer. Together they produce 70-85% smaller payloads.
Paste your CSS code into the input area and click Minify. The tool removes all whitespace, comments, and redundant characters while preserving full CSS functionality. Click Copy to get the minified output. Use the stats panel to see file size reduction percentage and byte savings.
CSS files commonly contain 30–60% redundant whitespace and comments. A 50KB CSS file minified to 20KB loads 2.5× faster for users. Google's PageSpeed Insights grades sites on CSS minification. Faster page speed improves Core Web Vitals scores, which are direct ranking factors in Google's algorithm.
Average CSS size reduction: 30–60%. Impact on TTFB: None (minification affects download, not server response). Impact on First Contentful Paint: Reduces time for render-blocking CSS to download. Gzip compression: Works better on minified files. Combined effect (minify + gzip): Often achieves 80–90% total size reduction vs. original. Always test visually after minification to confirm no breakage.