Developer — tool

CSS Formatter / Minifier

Format CSS consistently or optimize it for delivery.

About CSS Formatter / Minifier

Use Prettier for readable CSS and CSSO for minification with optional structural optimization.

CSS Formatter / Minifier uses Prettier to produce consistent readable CSS and CSSO to remove redundancy. Structural optimization can be disabled for a more conservative minification pass.

How to use it

  1. Paste standard CSS and choose formatting options.
  2. Format it or minify with the desired optimization level.
  3. Test the output in its real page before deployment.

Common use cases

  • Format a compact stylesheet for code review.
  • Reduce CSS before embedding it in a static page.
  • Detect parser errors while preparing a stylesheet for deployment.

Worked example

Turn a one-line component stylesheet into reviewable CSS, then compare its optimized size.

Limitations and responsible use

  • Structural optimization may combine or reorder compatible rules and can expose dependencies on CSS hacks.
  • The tool processes standard CSS, not Sass, Less, or build-tool-specific syntax.
  • Visual correctness still requires testing the resulting stylesheet in its actual document.

Frequently asked questions

What does structural optimization do?

It allows CSSO to restructure compatible rules for a smaller result. Disable it when preserving rule shape is more important.

Does minification guarantee the page looks identical?

No. Parser-safe output should still be tested against the real HTML and supported browsers.