CSS minifier
Paste a stylesheet to get the smallest equivalent CSS, with the exact size you save.
Sealed on this device
Runs in your browser. Nothing is uploaded.
Sealed
Minified CSS
Your minified CSS will appear here as you type.
How it works
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Paste your CSS
Paste a stylesheet or open a .css file. Minification starts as you type.
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Choose how far to go
Merging rules gives the smallest file. Turn it off if the order of your rules must stay exactly as written.
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Copy or download
See the size before and after, including gzip, then copy the result or download a .min.css file.
Frequently asked questions
Is my CSS uploaded?
No. Minification runs in your browser with the open-source CSSO engine. Your stylesheet never leaves your device.
What does minification remove?
Whitespace, line breaks, comments, the last semicolon of each block and redundant zeros and units. Colors are shortened, for example #ff0000 becomes red, and duplicate declarations are dropped.
What does “Merge and reorder rules” do?
It combines rules that share selectors or declarations and moves them when that’s safe, which often saves the most bytes. If your styles rely on an unusual cascade order, turn it off to keep the structure as written.
Why keep /*! comments?
Comments that start with /*! usually hold a license or copyright notice that must stay with the code. All other comments are removed.
What is the gzip size?
Web servers usually compress CSS before sending it. The gzip figure, measured in your browser, shows roughly how many bytes actually travel over the network.