A CSS formatter is a tool that automatically re-styles raw CSS code to make it easier to read and maintain. It adds consistent indentation, line breaks, and spacing - turning minified or hand-written CSS into clean, standardised code without changing how the styles actually behave in a browser.

Beautify and compact modes only change whitespace - they never alter property values, selectors, or declaration order (unless you enable the sort option). Your CSS will behave identically in a browser before and after formatting. Minify mode also only removes whitespace and comments, which have no effect on rendering. The sort option does reorder declarations, which is safe in the vast majority of cases but should be reviewed if your code relies on the cascade order of duplicate properties.

A CSS Formatter (or Beautifier) takes CSS code, which might be minified or inconsistently written, and reorganizes it with standard indentation, spacing, and line breaks to make it highly readable for developers without changing how the styles are applied by the browser.