CSS Beautifier
Minified or hand-mangled CSS arrives as one unbroken line: no indentation, no spacing between rules, declarations crammed end to end. It works in the browser but is impossible to read, review, or edit. This beautifier takes that wall of text and lays it back out the way a stylesheet is meant to look, with one declaration per line, consistent indentation, and a blank line between rules. It parses the CSS into a real syntax tree first, so the rendered result is untouched and only the formatting changes. Choose your indent style, and it all runs locally in your browser.
Overview
Reading a stylesheet you did not write, or one a build step flattened, starts with getting it back into a shape your eyes can follow. This tool does that without second-guessing what the CSS means.
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Parser-based reformatting
The CSS is read into a syntax tree before it is printed back out, so the tool understands selectors, blocks, and at-rules rather than guessing at line breaks. Formatting that comes from a parse tree cannot quietly corrupt a value or drop a rule.
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Consistent, predictable layout
Every declaration lands on its own line, nesting is indented the same way throughout, and neighbouring rules are separated by a blank line unless you switch that off. The same input always produces the same output, so the result is stable enough to commit and diff.
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Indent on your terms
Pick two spaces, four spaces, or tabs so nesting reads the way your team expects, then collapse or expand every block at once and toggle soft wrapping while you scan the result.
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At-rules and modern CSS understood
Media and container queries, supports blocks, layers, keyframes, custom properties, and nested rules are all laid out with the right indentation instead of being treated as plain text.
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Errors you can act on
When the CSS will not parse, the reason, the line and column, and a short excerpt of the offending code are shown together, so you can find the stray brace instead of guessing where the formatter gave up.
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Copy, download, or upload
Paste from the clipboard, open a .css file from disk, then copy the tidy result or save it. The whole loop stays on your machine and never touches a server.
How to use
Go from an unreadable block of CSS to a clean, consistently formatted stylesheet in a few steps.
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Paste your minified or messy CSS into the input panel, or use Upload to open a .css file from disk.
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Pick your indent style, and switch single quotes or the blank line between rules on or off to match your house style.
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Read the formatted CSS on the right, with one declaration per line and rules spaced out, updating as you adjust the options.
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Copy the result or download it as a .css file, then drop it into your editor to read, review, or keep working on.
Details
The details that make the formatted output trustworthy and easy to live with.
- Built on Prettier, which reformats from a parsed representation rather than by guessing where to insert line breaks.
- Formatting runs as you type and as you change options, with no button to press before the result updates.
- A syntax error is reported with its reason, its position, and the surrounding line, instead of producing half-formatted or empty output.
- Both the input and the formatted result are shown with full CSS syntax highlighting in light and dark themes.
- Nothing is uploaded or logged. The CSS you paste stays in your browser and is gone when you close the tab.
Use cases
Where turning dense CSS back into a readable form earns its keep.
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Reading a minified stylesheet
When the only copy of a stylesheet is the minified file in production or a CDN, format it here to see how the rules and selectors are actually structured.
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Reviewing vendor or generated CSS
Output from a framework, a CSS-in-JS tool, or a third-party widget often ships flattened. Beautifying it makes a code review or an audit possible.
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Debugging a specificity or override bug
Laid-out CSS makes it far easier to spot the duplicate selector, the misplaced declaration, or the at-rule that is quietly overriding your styles.
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Producing a clean diff
Format both versions of a stylesheet the same way, and a diff tool shows the real change instead of drowning it in whitespace noise.
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Tidying CSS you pasted in
Snippets copied from documentation, an answer online, or a chat thread arrive with inconsistent spacing. One pass normalises them to your indent style.
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Teaching and sharing examples
A consistently formatted stylesheet is easier to explain in a tutorial, a code comment, or a pull request than one with ad-hoc spacing.
See also
Shipping rather than reading? The CSS Minifier compresses the same CSS in the opposite direction, and for scripts the JavaScript Beautifier formats JavaScript the same readable way. And when the stylesheet is not a file of its own but sits inside a page, formatting the markup and the CSS in it in one pass is the HTML Beautifier.
Beautifying versus minifying
Beautifying and minifying are the same idea pointed in opposite directions: both only touch the characters a browser ignores, never the meaning. One adds the whitespace that makes CSS readable; the other strips it away.
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Formatting is reversible and safe
Adding indentation, line breaks, and spacing changes nothing about how the page renders. A browser treats one line and forty as identical, so beautifying is a presentation change for humans, not a rewrite of your styles.
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Why minified CSS is unreadable
A build step removes every optional space and newline to save bytes. That is ideal for shipping, but it leaves a single line where a selector, its block, and the next rule all run together with no visual boundary.
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It is not un-minifying
Beautifying restores layout, not the original source. Comments that minification stripped are gone for good, and any merged or reordered rules stay merged. You get readable CSS, not a byte-for-byte copy of what the author wrote.
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Idempotent by design
Formatting already-formatted CSS produces the same text again. Because the output is deterministic, it is safe to run on every save or in a pre-commit hook without creating noisy, churn-only diffs.
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Standard CSS only
This formats plain CSS. Sass, Less, and other preprocessor syntax must be compiled down first, since the parser expects the CSS a browser would actually receive.
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A reading and reviewing tool
The point is comprehension: making a flattened or unfamiliar stylesheet easy to scan, diff, and reason about. For shipping, you still minify, which is the mirror image of this step.
Best practices
Habits that get the most out of formatting CSS.
- Use the beautifier to read and review, but keep the original readable source as your source of truth when you have it.
- Pick one indent style for a project and stick to it, so formatted files diff cleanly against each other.
- Keep the blank line between rules while you are reading unfamiliar CSS, and turn it off when you want the shortest readable form to paste somewhere else.
- Remember that formatting will not bring back comments or undo merged rules that minification removed; it restores layout, not the original source.
- For your own codebase, wire a formatter into your editor or a pre-commit hook so files stay consistent without a manual paste each time.
- Compile Sass or Less to plain CSS before formatting, since preprocessor-only syntax is not valid CSS on its own.
Limitations
What this tool does, and what it leaves to other steps.
- It reformats a single block of standard CSS. It does not bundle imports, resolve URLs, or add vendor prefixes.
- It restores layout, not lost information. Comments and structure removed by minification do not come back.
- Preprocessor sources such as Sass, Less, or Stylus must be compiled to CSS first, since only standard CSS parses here.
- A syntax error stops formatting and is reported with its position, so badly broken input will not silently produce partial output.
- Files are read in the browser, so uploads are capped at 2 MB. Anything larger is better opened in your editor.
FAQ
Common questions about formatting CSS and when to reach for it.
Does beautifying change how my CSS renders?
No. It only adds the whitespace and line breaks a browser ignores: indentation, spacing between rules, and one declaration per line. Selectors, values, and at-rules keep their meaning; the only rewriting is cosmetic, such as printing a length as 0.5rem rather than .5rem, so the rendered page looks exactly the same before and after.
Can it fully reverse a minifier?
It reverses the layout, not the information. Beautifying restores readable spacing and indentation, but comments that the minifier stripped are gone, and any rules it merged or reordered stay that way. You get clean, readable CSS, not a byte-for-byte copy of the original source.
What formatting options are there?
You can indent with two spaces, four spaces, or tabs, and choose whether neighbouring rules are separated by a blank line. The single-quote option switches string and url() quoting where it is safe to do so, and you can collapse, expand, or soft-wrap the output while you read it.
What happens if my CSS has a syntax error?
Formatting stops and the tool shows what went wrong: the reason, the line and column, and the line itself with a marker under the problem. Nothing half-formatted is produced, because a formatter that guesses its way past a stray brace would be rearranging code it does not understand.
Can I format Sass, Less, or SCSS here?
Not directly. This tool formats standard CSS, which is what a browser receives. Compile your Sass or Less to CSS first, then paste that output here, or use a formatter that understands your preprocessor syntax.
Will it keep my media queries and custom properties intact?
Yes. Media and container queries, supports blocks, layers, keyframes, custom properties, and nested rules are parsed and laid out correctly. The structure is understood rather than treated as plain text, so valid CSS comes back with its meaning intact.
Is my CSS uploaded anywhere?
No. Everything runs in your browser. The CSS you paste and any file you open are processed locally, never transmitted or stored, and disappear when you close the tab, so vendor styles and unreleased work stay private.
Related tools
Keep going with the rest of the data and format toolkit.