CSS Minifier & Formatter
Minify or beautify CSS in your browser. Comments, whitespace, and license blocks are handled safely. Nothing is uploaded.
Minification removes whitespace, comments and duplicate declarations while preserving calc(), media queries, custom properties and /*! license comments. Read the diff before shipping, since a minifier bug is silent.
Tool workspace
Result
How to Minify CSS Online
Paste CSS and get minified or formatted output locally, without uploading.
- 1
Paste your CSS
Copy the stylesheet or rule block into the input area.
- 2
Choose a mode
Select Minify to compress or Beautify to expand with indentation.
- 3
Copy the result
Copy the output and verify the rendered result before deploying.
Common Use Cases
- 1Shrink CSS before deploying to reduce payload size and page weight
- 2Beautify minified or generated CSS before debugging or reviewing
- 3Remove comments from production bundles while keeping license blocks
- 4Normalize whitespace from copied snippets so diffs stay readable
Frequently Asked Questions
Does the tool upload my CSS?
No. Minifying and formatting run entirely in your browser. You can confirm by opening DevTools → Network and watching for requests while pasting.
What does the minifier do?
It removes comments and redundant whitespace, drops the last semicolon of each rule, and preserves string literals and url() values. License comments are kept when the option is enabled.
Can I beautify already-minified CSS?
Yes. Switch to Beautify mode and paste minified CSS — rules, properties, and nested blocks are re-indented for readability.
Is minified CSS semantically identical?
The minifier removes comments and redundant whitespace, drops the final semicolon in a rule, and preserves strings and url() values. Test the output on a staging page if a stylesheet relies on unusual hacks.
How large a stylesheet can I process?
Each run accepts up to 1 MB, which covers most hand-written and bundled stylesheets. Larger files are rejected with a message instead of blocking the tab.
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You are responsible for key management and output validation.