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CSS Minifier Online

Minify CSS by removing whitespace, comments, and applying safe optimizations — reducing file size without changing behavior.

Runs entirely in your browser — your files are never uploaded to a server.

Last updated

This tool processes your input entirely in your browser. Nothing is sent to our servers.

How It Works

1. Choose Your File

Drag & drop or select the file you want to work with.

2. Processed in Your Browser

Everything happens locally on your device — your file is never uploaded anywhere.

3. Download Your Result

Get your finished file instantly, ready to save or share.

About CSS Minifier Online

Minifying CSS removes unnecessary whitespace, comments, and line breaks that make a stylesheet readable for humans but add nothing functional — reducing file size for faster page loading without changing how anything renders.

This matters specifically for production websites, where every additional kilobyte affects load time — the visual result is identical, only the file’s actual size changes.

Keep your original, readable (unminified) CSS as your working source file — minified CSS is meant for deployment, not for ongoing editing, since it’s deliberately stripped of the formatting that makes it easy to read and modify.

Frequently Asked Questions

How to minify CSS?

Paste your CSS into the box and click Minify CSS. The tool strips whitespace and comments, shortens values where safe, and shows the original and minified size in bytes. Copy the output with the copy button and use it in place of your original.

How to minify a CSS file?

Open the stylesheet in a text editor, copy everything and paste it into the tool. Then save the minified output as a new file, such as style.min.css, and keep your readable original. There is no file upload button, so it works on pasted text.

How to minify CSS in WordPress?

Minify your stylesheet here, then paste the result into a child theme file or the Additional CSS box, keeping the original as a backup. Core WordPress does not minify theme CSS on its own, so many sites rely on an optimization plugin instead.

Can minifying change how my CSS behaves?

Possibly. The tool uses CSSO, which optimizes structure, so it can merge and reorder rules. That is normally safe, but check your pages after swapping in the minified file. It only minifies and has no option to beautify or expand CSS.

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