CSS and JS Minifier

Minify CSS or JavaScript snippets

This JS and CSS minifier makes a code snippet smaller by removing comments and extra whitespace. It is a lightweight tool for quick jobs, such as shrinking an embed or a demo, not a replacement for a full build tool like a bundler or compressor.

How to use it

1. Choose CSS or JavaScript mode.
2. Paste your code into the Source code box. The minified output updates as you type.
3. Compare the original and minified character counts and the characters saved.
4. Click Copy output to copy the result.

What the minifier removes

CSS mode

• Removes /* ... */ comments.
• Collapses all whitespace to single spaces, then removes spaces around { } : ; , > + ~.
• Drops the last semicolon before a closing brace.

JavaScript mode

• Removes /* ... */ comments and lines that start with //.
• Collapses whitespace and removes spaces around brackets, operators and punctuation.

Example in CSS mode:

.card {
  padding: 16px;
  margin: 0 auto;
}

becomes .card{padding:16px;margin:0 auto}.

Limitations to check before using the output

• The tool uses simple text patterns, not a code parser. It does not rename variables or shorten values.
• In JavaScript, a // comment at the end of a line of code is not removed. Because line breaks are removed too, it can comment out the code after it.
• Code that relies on line breaks instead of semicolons may break once lines are joined.
• Spaces inside strings and template literals are also collapsed.
• In CSS, spaces around + are removed, which breaks calc() expressions such as calc(100% + 10px).

Always test the minified code before using it.

Frequently asked questions

Is my code uploaded?

No. Minifying runs in your browser. The optional Save to history button keeps recent snippets in this browser only (local storage), on your own device.

Can I use it for production builds?

For large apps, use your normal build pipeline. This tool is best for short snippets and quick tests.