Compress a stylesheet and see exactly how many bytes you saved
Runs in your browser. Nothing you type is sent anywhere. Updated on 25 Oct 2026.A stylesheet is one of the first things a browser must fetch before it can paint, so its size shows up directly in how quickly a page appears. This page strips comments and whitespace, shortens colours and units, and can merge rules that share a block. You get the size before, the size after and the percentage saved, then copy or download the result.
The page opens in Minify mode; paste the stylesheet into the CSS box.
Leave Restructure on to merge duplicate rules, or turn it off for a diff that shows only whitespace.
Turn on Keep licence comments if the licence header must stay in the file.
Read Before, After and the percentage smaller, then press Copy or Download.
This CSS formatter has two modes. Beautify lays a stylesheet out with one declaration per line, even indentation and consistent spacing around colons and braces. Minify strips comments and whitespace, shortens colours and units, and can merge rules that share the same block, then shows the size before, the size after and the percentage saved.
Minifying uses csso. The restructure option is the aggressive part: it merges rules with identical blocks, removes declarations that a later rule overrides and reorders where that is safe. It usually saves a few more percent and the result is equivalent, but if you are auditing a diff or your CSS depends on source order in ways a tool cannot see, turn it off and only whitespace and comments go. Comments beginning with an exclamation mark, which is where licence headers live, can be kept.
Above the result you get the number of rules, selectors, declarations and at-rules. If a brace, comment or quote is left open, you get the line and column where it started and what to add, rather than a parser dump. Everything runs in your browser, so a stylesheet from an unreleased project is never uploaded anywhere.
The rest of the article, and all 6 questions about CSS Beautifier & Minifier, are on the CSS Beautifier & Minifier page.
Yes. No signup, no file size limit and no cap on how many stylesheets you run through it. The page is supported by a few ads shown outside the tool, and your result is never touched by them.
No. Beautifying and minifying both run in your browser with JavaScript. A stylesheet from an unreleased design or an internal admin tool never leaves your device, and nothing is kept once you close the tab.
A hand-written stylesheet with comments and indentation usually drops 15 to 30 percent, and restructure adds a couple of points more on top by merging duplicate rules. The page shows the exact byte count before and after, so you never have to guess.
Minifying should not break a valid stylesheet. csso parses the CSS properly rather than using text replacement, so strings, data URIs and custom properties survive. If the file cannot be parsed you get the line and column instead of a broken result, and nothing is copied.
Still stuck? Ask about CSS Beautifier & Minifier and anybody who knows can answer. No account needed.
Same job, other tools: HTML Minifier – Strip comments and spare whitespace from HTML and see the saving · JSON Minifier – Strip whitespace from JSON for production · JS Minifier – Shrink a JavaScript file with terser and see the size saved.
On the related tools: GraphQL Validator – Check a GraphQL query or schema for errors, optionally against your own SDL.
In the collection Code Formatters and Minifiers.