CSS Beautifier
Turn minified or hand-mangled stylesheets back into clean, consistently formatted CSS you can actually read and edit.
What is a CSS beautifier?
A CSS beautifier reformats stylesheet source so each rule, selector and declaration sits where you'd expect it — properties on their own lines, braces aligned, blocks separated. It's the tool you reach for when you open a production .css file and find the whole thing crammed onto two lines.
This formatter parses your CSS into an abstract syntax tree with css-tree and regenerates it cleanly, which means malformed CSS is caught rather than silently mangled. Selectors, media queries, custom properties and nested at-rules are all understood, not just blindly re-spaced.
Everything runs in the browser, so proprietary design-system CSS never leaves your machine.
How to beautify CSS
- 1
Paste your CSS
Add minified or messy CSS to the input pane, or upload a .css file.
- 2
Get clean output
The beautified, indented stylesheet appears in the output pane automatically.
- 3
Review structure
Scan the formatted rules — selectors, declarations and media queries are now clearly separated.
- 4
Copy or download
Copy the result to your clipboard or save it as a .css file.
Where it helps
Read compiled output
Inspect the CSS that a build tool or framework actually shipped, formatted so you can trace a rule.
Clean up legacy files
Bring inconsistent, hand-edited stylesheets to a single predictable format before refactoring.
Easier code review
One declaration per line means smaller, clearer diffs when CSS changes land in a PR.
Spot syntax errors
A missing brace or stray semicolon surfaces during parsing instead of breaking your layout silently.
Example: before and after
Minified input on the left, beautified output on the right.
.btn{color:#fff;background:#0070dc;padding:8px 16px}.btn:hover{background:#005bb5}.btn {
color: #fff;
background: #0070dc;
padding: 8px 16px;
}
.btn:hover {
background: #005bb5;
}Why minified CSS is so hard to read
Build pipelines strip every optional byte from CSS: newlines, indentation, the last semicolon in a block, even spaces around colons. That's perfect for download speed and miserable for humans. Beautifying reverses those optimisations so you can understand what a rule does before changing it. When you're done, push it back through a CSS minifier for production.
What stays exactly the same
- Your selectors and specificity — nothing is renamed or reordered in a way that changes behaviour.
- Property values, units and colour formats are preserved as written.
- Media queries,
@supports, keyframes and custom properties keep their meaning. - Only whitespace and layout change; the rendered result is identical.
Frequently asked questions
No. Beautifying only adds whitespace and line breaks. The selectors, properties and values are untouched, so the rendered result is exactly the same.
Yes. Paste minified CSS and you'll get a readable, indented version back. It's the fastest way to inspect what a bundler or framework shipped.
No. Parsing and formatting are done locally with css-tree in your browser, so your stylesheets stay private.
The parser will flag it instead of producing scrambled output. Fix the reported issue — usually a missing brace or semicolon — and the formatted result appears.
It understands standard modern CSS including custom properties, media queries, and at-rules. Highly experimental syntax may not be recognised, but everyday production CSS is well supported.
Commit the readable, beautified source and let your build step minify for production. That keeps diffs clean while still shipping small files to users.
Need another tool?
Browse the full toolbox or dig into the blog for the engineering behind it.