CSS Minifier

The minifier tokenizes your stylesheet before changing anything, so strings (content: " /* not a comment */ ") and url() values are protected. It then applies only safe transformations: removes comments except those starting with /*! (the convention for license banners), collapses whitespace, removes spaces around { } : ; , and selector combinators, and drops the last semicolon in each block.

Values are shortened where the result is guaranteed to be equivalent: 0px → 0 for length units, 0.50em → .5em, #aabbcc → #abc. Zeros are left alone inside calc() and other functions — calc(100% - 0px) is valid but calc(100% - 0) is not — and for % and time units, because 0s and 0% are not interchangeable with 0 everywhere. Custom property values (--x: 0px) are kept verbatim since they may be used inside calc(). Selectors are never rewritten, so an ID like #aabbcc is safe.

Typical savings are 15–30% before compression. The status line also shows the gzip size, which is what users actually download when your server compresses responses. The tool does not merge rules or remove unused CSS; for that, use a build step with cssnano, Lightning CSS or PurgeCSS. Everything runs in your browser.