CSS Minifier
Strip comments and whitespace from CSS to shrink your stylesheet. Browser-only, free.
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About CSS Minifier
The CSS minifier removes comments, collapses whitespace, and drops the optional final semicolon in each rule to produce a smaller stylesheet that renders identically. Real-world CSS minification can also rewrite property values (#ffffff → #fff, 0px → 0), but this tool keeps it simple and safe — only whitespace and comments are touched.
When to use it
- Reducing CSS payload before HTTP compression
- Inlining a stylesheet into a single attribute or template
- Stripping authoring comments before publishing
- Producing a more compact CSS string for a CSS-in-JS escape hatch
How it works
A regex pass removes /* ... */ comments. A second pass collapses runs of whitespace inside the document into single spaces and removes whitespace around braces, colons, semicolons, and commas where it isn't significant.
Examples
Comments removed, whitespace collapsed
/* main button */
.button {
background: #ffffff;
color: #000000;
padding: 0.5em 1em;
}.button{background:#ffffff;color:#000000;padding:0.5em 1em}Frequently asked questions
- Will my page render the same?
- Yes. Comments and whitespace are not significant in CSS. The cascade and specificity rules apply identically to the minified output.
- Does it rewrite values like colors or zero units?
- No. To keep the tool simple and safe, value-level optimizations (#ffffff → #fff, 0px → 0, removing duplicate rules) are not performed. For aggressive minification, use a real CSS minifier like cssnano or lightningcss in your build.
- What about CSS comments inside strings?
- Strings inside content: properties are scanned and preserved, but the simple regex pass may produce incorrect output for unusual cases. Verify the result before shipping.
- Is the file uploaded?
- No. Minification runs entirely in your browser.