What this tool does
CSS Minifier
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Use this page when the task is direct action. The interface is visible immediately, the workflow is clear, and related internal links keep adjacent tasks close.
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Process a complete static website ZIP
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Check website ZIP eligibilityHow to use this tool
How to minify CSS
Paste CSS or upload one CSS or text file up to 1 MB.
Choose comment, whitespace, zero-value, color, and aggressive cleanup options.
Select Minify CSS and compare the output with the tested example.
Test important pages and states before deploying the generated file.
Before and after example
CSS minification example
Input
.button {
padding: 12px 16px;
color: #ffffff;
}Output
.button{padding:12px 16px;color:#fff}Options, errors, and limitations
CSS options, limitations, and output testing
Parent category
Explore the Minify Tools hub
Pages focused on CSS, HTML, JavaScript, and JSON minification workflows.
Related articles
Read more from the developer blog
FAQ
CSS Minifier FAQ
How can smaller CSS reduce transferred bytes?
Minification removes source characters before the stylesheet is sent. Fewer source bytes can reduce the uncompressed resource size, while the actual network transfer also depends on caching and HTTP compression.
Does CSS Minifier remove unused CSS?
No. It transforms the submitted stylesheet without knowing which selectors a site uses. Use browser coverage data or a build tool to identify unused rules, then test every affected template and state before deleting them.
Is CSS minification the same as Brotli or gzip?
No. Minification rewrites the source into a smaller text representation. Brotli or gzip is applied by the server or CDN while transferring that representation; production sites commonly use both.
Which CSS options are available?
The interface can remove comments and whitespace, shorten supported zero units and six-digit hex colors, and apply an aggressive cleanup mode. The service also removes safe final semicolons when that form option is submitted.
Does the tool preserve license comments?
No special license-comment exception is implemented. If Remove comments is selected, CSS block comments are removed, so preserve required notices separately or leave that option off.
Can aggressive mode change CSS behavior?
It applies additional text substitutions and needs extra review. Test responsive breakpoints, custom properties, calc expressions, pseudo-classes, animations, and any legacy syntax used by the project.
Should I keep the readable stylesheet?
Yes. Keep reviewed source in version control and generate minified output as a deployment artifact so debugging, code review, and rollback remain practical.
Can the tool prove a page will load faster?
No. It reports byte differences for the submitted text. Real loading depends on the stylesheet size, cache state, compression, latency, render blocking, unused rules, and the rest of the page.