A stylesheet pulled from a built bundle or copied out of browser developer tools is one long line, and finding the rule that is winning a specificity fight means reading it properly.
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CSS Formatter
Css
Free · API · MCPToolYour platform
Use CSS Formatter three ways
The free CSS Formatter on this page works in your browser. The same workflow is available via REST API for apps and via MCP for Cursor, Claude, and other agents — one API key, one plan, one quota. This tool is part of the developer-apis module under Developer Tools.
- Free in browserUse CSS Formatter here — no account required.
- REST APICall from your server with
X-Api-Key. - MCP for agentsConnect Cursor or Claude to ToolYour MCP with the same key.
- 1. Get an API keySign in and open Dashboard → API Keys (works for REST and MCP).
- 2. Call or connectUse the REST API from your server, or paste the MCP URL into your agent config.
- 3. Same qualityOutput matches the free web tool across all three surfaces.
What is CSS Formatter?
A stylesheet pulled from a built bundle or copied out of browser developer tools is one long line, and finding the rule that is winning a specificity fight means reading it properly. This CSS formatter runs Prettier over the input, putting one declaration per line with consistent spacing around selectors, braces, and at-rules.
Prettier parses the CSS first, so a stray brace or an unterminated comment produces an error rather than mangled output. The scope is formatting: it does not compile Sass or Less, run PostCSS plugins, add vendor prefixes, check browser support, or lint for problems the way stylelint would. Nested syntax from a preprocessor should be compiled to plain CSS before you paste it. Once the stylesheet is readable and correct, CSS Minifier compresses it again and reports the byte difference.
Browser use is free and needs no signup. The same job runs over REST at POST https://api.toolyour.com/api/v1/developer-apis/css-formatter and over MCP at https://api.toolyour.com/mcp — one API key, one shared monthly credit pool, 1 credit per successful call.
What are common questions about CSS Formatter?
Does it handle Sass or Less?
This path targets plain CSS. Compile preprocessor syntax first, since nested rules and variables may not parse as written.
Will it add vendor prefixes?
No. Prefixing is Autoprefixer's job and depends on your browser support targets, which a formatter cannot know.
Does it minify as well?
No, that is the opposite job. Use CSS Minifier when you want compression and a byte-count comparison.
What are the key features of CSS Formatter?
Prettier CSS printing
One declaration per line with consistent spacing, matching common repository style.
Syntax errors caught
Unbalanced braces and broken comments fail the parse rather than producing odd output.
Specificity made visible
Readable selectors make it far easier to see which rule is actually winning.
How do you use CSS Formatter?
Paste the CSS
A bundle extract, a component stylesheet, or rules copied from developer tools.
Format
Read the rules and spot duplicated or conflicting selectors.
Edit and re-minify
Make your change, then compress with CSS Minifier if you are shipping the file directly.
What readable CSS reveals
Formatting is often the step that ends a styling argument. Duplicate selectors — the same selector defined twice, hundreds of lines apart, with the later one silently winning. Specificity escalation — a chain of increasingly specific selectors, each added to beat the last, which reads as a clear pattern once indented. Dead media queries — a breakpoint that can never match because an earlier query already covered the range.
None of these are syntax errors, so no tool flags them automatically. They are visible to a person reading formatted rules, which is exactly why the formatting step is worth taking before the debugging step.
Format for review, minify for delivery
Keep the two directions separate and it stays simple. Repositories hold formatted CSS because that is what humans review and diff. Production serves minified CSS because that is what users download.
The transition belongs in your build. When you are hand-editing a file that ships directly, CSS Minifier closes the loop and shows the byte saving. If the stylesheet lives inside a page you are also inspecting, HTML Formatter makes the surrounding markup readable at the same time.
Which formatter and utility tools sit in this cluster?
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Browse the full Developer Tools category on ToolYour.
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