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CSS Formatter — Beautify CSS Stylesheets Online

CSS Formatter uses Prettier to apply consistent formatting to your CSS stylesheets. It handles standard CSS, multi-selector rules, media queries, and pseudo-classes.

CSS Formatting Rules

Formatted CSS places each declaration on its own line with consistent indentation, puts the opening brace on the same line as the selector, and adds a blank line between rule sets. This style is enforced by Prettier — the same formatter used by millions of JavaScript projects — ensuring the output is compatible with any CSS linter or style guide.

Minified CSS from production builds collapses all whitespace, making debugging nearly impossible. Pasting minified CSS into this formatter restores the full indented structure without changing any property values or selector specificity. The formatted output is functionally identical to the minified original.

Media Queries and Nesting

The formatter correctly handles @media, @keyframes, @supports, and @layer blocks, applying extra indentation to the rules inside the at-rule block. CSS custom properties (--my-variable: value) are preserved exactly. CSS nesting (the new native CSS nesting specification, now supported in all major browsers) is also supported through the Prettier Babel CSS parser.

For very large stylesheets (hundreds of rules), the formatted output is easier to read in a code editor than in a browser text area. Copy the formatted output and paste into VS Code, which applies syntax highlighting. Use Ctrl+F to search for specific selectors or properties.

Common Use Cases

  • Formatting minified CSS copied from production assets
  • Standardizing CSS formatting across a team
  • Beautifying CSS before adding to version control

Frequently Asked Questions

Does CSS formatting change the visual output?

No. CSS formatting only changes whitespace and indentation. The resulting CSS applies the same styles as the original.

Privacy & Security

This tool runs entirely in your browser using client-side JavaScript. No data is sent to a server — your input never leaves your machine. SmartDevBox has no account system, no usage tracking, and no paid tier. See the Privacy & Security page for full details.

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