Will minifying break my styles?

No — only comments and non-meaningful whitespace are removed; the actual selector and property values stay unchanged.

Does this merge duplicate selectors or shorten colors?

No — this is a lightweight textual minifier, not a full optimizing minifier. Duplicate rules and color format shortening aren't performed.

How much size reduction should I expect?

Typically 15-30% for well-commented, indented source CSS, though results vary by how verbose your original formatting is.

Is my CSS uploaded anywhere?

No — minification runs entirely in your browser.

Does this handle CSS custom properties (variables)?

Yes — custom property declarations and usage (--variable-name) pass through unaffected by minification.

Free Online CSS Minifier

Strip Comments and Whitespace From CSS to Reduce File Size

Need to use CSS Minifier right now?

Well-formatted CSS with comments and consistent indentation is great for maintaining a stylesheet, but every one of those bytes gets downloaded by every visitor on every page load. This tool strips comments and collapses unnecessary whitespace around selectors, braces, colons, and semicolons, shrinking the file without changing any actual styling behavior.

No sign-upNo uploads 100% free

84 → 52 characters (38% smaller)

.card{padding:16px;color:#333}.title{font-size:20px}

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Features

Runs entirely in your browser
Privacy-first — your data is never uploaded
Real-time, instant results
100% free, no sign-up required
Works on desktop, tablet, and mobile
No installation needed

Who uses this tool?

Software engineersWeb developersAPI testersDevOps engineersStudents

People also search for

Minify CSS Online CSS Compressor JSON Formatter tool JSON Validator tool JSON Minifier tool

About CSS Minifier

The minifier removes CSS comments entirely, tightens spacing around punctuation (`{`, `}`, `:`, `;`, `,`) down to the minimum needed, and removes the final semicolon before a closing brace where it's redundant. These are purely textual transformations that preserve the exact same computed styles.

This is a lightweight, safe minifier — it doesn't merge duplicate selectors, shorten color values, or perform other more aggressive optimizations a build-tool-level minifier like cssnano would. For quick manual minification of a stylesheet before deployment, it still delivers a meaningful size reduction with zero risk to how your styles render.

How it works

Paste your CSS. Any formatted stylesheet.
Comments and whitespace strip automatically. See the size reduction percentage live.
Copy the minified result. Ready to deploy as a smaller stylesheet.

Examples

Minifying a formatted stylesheet

Input

.card {\n  padding: 16px;\n  color: #333;\n}

Output

.card{padding:16px;color:#333}