CSS Minifier Online
Shrink your stylesheets for faster page loads — comments stripped, whitespace collapsed, zero units and hex colors shortened. Private by design: everything runs in your browser.
178 chars in → 112 chars out (37% smaller)
Safe by design: strings, url() values and /*! … */ license comments are preserved exactly. The minifier strips comments, collapses whitespace, drops the last semicolon in each rule, removes units from zero values (0px → 0), and shortens hex colors (#ffffff → #fff).
Related guide
Read guide: CSS minifier (safe minification, size savings, workflow) →
Minify CSS (free, no signup)
Every extra byte of CSS slows your page down. This free CSS minifier compresses your stylesheet in one paste: comments removed, whitespace collapsed, the trailing semicolon in each rule dropped, 0px shortened to 0, and #ffffff shortened to #fff. The browser renders the result identically — visitors just get a smaller, faster file.
Unlike naive find-and-replace minifiers, this one is string-aware: quoted strings and url() values are never altered, so content: "a; b" survives minification intact. License headers in /*! … */ comments are preserved too (toggle it off if you want every byte gone).
Common use cases
- Shrink stylesheets before deploying to production
- Improve Core Web Vitals by cutting CSS download size
- Clean up commented-out experiments from hand-written CSS
- Prepare a style.min.css alongside your readable style.css
Minifying the markup too? ToolsOfWeb’s HTML Formatter minifies HTML the same safe way. For API payloads, the JSON Formatter minifies JSON with one click.
FAQs
What does a CSS minifier do?+
A CSS minifier shrinks your stylesheet by removing everything the browser does not need: comments, extra whitespace, the last semicolon in each rule, units on zero values (0px → 0), and long hex colors (#ffffff → #fff). The styles render identically — the file is just smaller and downloads faster.
Is my CSS uploaded to a server?+
No. Minification runs entirely in your browser. Your stylesheet never leaves your device, which makes this safe for proprietary or client CSS.
Can minifying break my CSS?+
A safe minifier never touches the parts that matter: quoted strings, url() values, and /*! … */ important comments (often license headers) are preserved byte-for-byte. This tool keeps all three intact.
How much smaller will my CSS get?+
It depends on how the CSS was written. Hand-written stylesheets with comments and generous spacing typically shrink 20–40%. Already-compact CSS shrinks less. The tool shows your exact saving live as you paste.
Does minified CSS improve SEO?+
Indirectly. Smaller CSS files load faster, and page speed is a Google ranking factor (Core Web Vitals). Minification is one of the cheapest performance wins on any site.
More free tools
Want guides and tips? Visit the ToolsOfWeb blog or go back to the homepage.
Related guide
Read guide: CSS minifier (safe minification, size savings, workflow) →