Upload your CSS and format it into a clean, easy-to-read stylesheet, then download the formatted CSS file instantly.
Beautify and format CSS code instantly in your browser. XConvert's free CSS Formatter adds proper indentation, consistent spacing, and organized line breaks so your stylesheets are easy to read, review, and maintain — no server uploads, no installations.
Step 1 — Paste or Upload Your CSS
Open the XConvert CSS Formatter and paste your minified or messy CSS into the input panel. You can also drag-and-drop a .css file directly onto the editor. The tool accepts any CSS — from a single rule to an entire stylesheet with thousands of selectors.
Step 2 — Choose Your Formatting Options Select your preferred indentation (2 spaces, 4 spaces, or tabs) from the toolbar. You can also toggle options like placing each selector on its own line, adding a blank line between rule blocks, and aligning colons in property declarations. These options let you match your team's coding style.
Step 3 — Click "Format" Press the Format button. The tool parses your CSS entirely inside your browser, restructures the whitespace according to your chosen options, and renders the result with syntax highlighting. Selectors, properties, values, and comments each receive distinct colors for easy scanning.
Step 4 — Copy or Download the Result
Click Copy to place the formatted CSS on your clipboard, or click Download to save it as a .css file. The output is ready to paste into your project, code editor, or version-control system.
CSS formatting — also called CSS beautifying or pretty-printing — is the process of restructuring a stylesheet's whitespace to make it human-readable. A formatter adds consistent indentation inside rule blocks, places each property declaration on its own line, inserts spaces after colons and before opening braces, and separates rule blocks with blank lines. The result is a stylesheet where the visual structure mirrors the logical structure, making it easy to scan and navigate.
The CSS itself does not change functionally. Every selector, property, value, media query, and comment remains identical. Only the visual layout improves. This distinction is important: formatting is a lossless, reversible operation that you can undo at any time by running the CSS through a CSS Minifier. You can freely switch between formatted and minified versions without any risk of data loss or behavioral changes.
Well-formatted CSS is essential for collaboration. When multiple developers work on the same stylesheet, consistent formatting reduces merge conflicts, makes code reviews faster, and helps newcomers understand the codebase. It also makes it easier to spot issues like duplicate properties, overly specific selectors, missing semicolons, or vendor-prefixed properties that lack their unprefixed counterparts. Teams that enforce consistent CSS formatting spend less time on style debates and more time on design and functionality.
| Feature | XConvert CSS Formatter | Prettier (CLI/IDE) | Stylelint --fix | Online Alternatives |
|---|---|---|---|---|
| Cost | Free | Free | Free | Free / Freemium |
| Installation | None (browser-based) | Required | Required | None |
| Privacy | Client-side only | Local | Local | Often server-side |
| Syntax Highlighting | ✅ | Editor-dependent | ❌ | Varies |
| Custom Indentation | ✅ | ✅ | ✅ | Varies |
| Selector-per-Line | ✅ | ✅ | ✅ | Varies |
| Drag-and-Drop Upload | ✅ | ❌ | ❌ | Varies |
| Works Offline | ✅ (after page load) | ✅ | ✅ | Rarely |
| Linting / Error Detection | Basic | ❌ | ✅ | Varies |
Unminifying Production CSS — When debugging a live website, you often encounter minified stylesheets. Paste the minified CSS into the formatter to restore readability and trace which rules affect a given element. This is invaluable when browser DevTools alone are not enough to understand complex cascade interactions.
Standardizing Team Style — Before committing CSS to a shared repository, format it with consistent settings. This eliminates style debates in code reviews and keeps diffs clean. When every developer uses the same formatting, pull request reviews focus on logic rather than whitespace.
Reviewing Third-Party CSS — When evaluating a CSS library, framework, or theme, formatting the source makes it easier to understand the structure, identify overrides you need, and assess code quality. Many popular frameworks ship minified CSS, so formatting is the first step in any evaluation.
Preparing Documentation Examples — CSS snippets in tutorials, blog posts, or API docs should be well-formatted so readers can follow along without confusion. Consistent indentation and spacing make examples look professional and reduce reader cognitive load.
Refactoring Stylesheets — Before a major refactor, format the entire stylesheet so you can see the full structure clearly. This helps you identify redundant rules, unused selectors, opportunities to consolidate media queries, and properties that can be combined into shorthand declarations.
Learning CSS — Beginners benefit from seeing CSS in a clean, structured form. The visual hierarchy of selectors and properties reinforces how the cascade and specificity work. Formatted CSS also makes it easier to experiment with changes and see their effects in context.
XConvert's CSS Formatter uses a client-side CSS parser that tokenizes the input into selectors, declarations, at-rules, and comments. Unlike a simple regex-based approach, the parser understands CSS grammar, which means it correctly handles edge cases like nested at-rules (@media, @supports, @keyframes), multi-selector groups, shorthand properties, calc() expressions with internal whitespace, and CSS custom properties with complex fallback values. The parsed token stream is then reassembled with the user's chosen indentation and spacing rules, producing clean, consistent output regardless of how messy the input was.
Syntax highlighting is applied during the output rendering phase. Selectors are colored differently from property names, which are colored differently from values. Strings, numbers with units, color hex codes, and function calls like rgb(), var(), and clamp() each receive their own styling. This makes it easy to scan a large stylesheet and quickly locate the section you need. The color scheme meets WCAG AA contrast requirements for accessibility, ensuring the tool is usable by developers with color-vision deficiencies.
All processing runs in the browser with no server communication. Your CSS — which may contain internal class names, proprietary design tokens, or unreleased feature styles — stays on your machine. The formatter handles stylesheets up to several megabytes and works in all modern browsers including Chrome, Firefox, Safari, and Edge. For extremely large files, consider splitting them into logical partitions (layout, components, utilities) before formatting. After formatting, you can use the CSS Minifier to compress the stylesheet back down for production deployment, or paste it into the HTML Formatter if it is part of an inline <style> block.
Pick One Indentation Style — Choose 2 spaces, 4 spaces, or tabs and use it consistently across your entire project. Mixing indentation styles creates noisy diffs and confuses collaborators.
One Selector Per Line — For rule blocks with multiple selectors (e.g., h1, h2, h3 { ... }), enable the option to place each selector on its own line. This makes it easier to see which elements a rule targets and simplifies future edits.
Preserve Comments — The formatter keeps all CSS comments intact. Use comments to document sections, explain hacks, or note browser-specific workarounds. They will survive formatting and subsequent minification if you configure the CSS Minifier to preserve important comments.
Format Before Reviewing — Run CSS through the formatter before submitting it for code review. Reviewers can focus on logic and design decisions rather than whitespace inconsistencies.
Combine with Minification — Use the formatter during development for readability, then run the CSS Minifier as a build step to strip whitespace before deploying to production.
Check for Syntax Errors — If the formatter produces unexpected output, your CSS may contain syntax errors (e.g., missing semicolons, unclosed brackets). Fix these issues in your editor and re-format.
No. All processing happens client-side in your browser. Your CSS never leaves your device, making it safe for proprietary or unreleased stylesheets. There are zero network requests after the initial page load.
No. Formatting only modifies whitespace — spaces, tabs, and newlines. Every selector, property, value, and comment remains functionally identical. The visual presentation changes, but the browser interprets the CSS exactly the same way.
You can choose 2 spaces, 4 spaces, or tab characters. The default is 2 spaces, which is the most common convention in front-end development.
The formatter is designed for standard CSS. SCSS and LESS files that use variables ($color, @color), mixins, nesting, or other preprocessor-specific syntax may not parse correctly. Use a dedicated SCSS/LESS formatter for those preprocessor syntaxes, then format the compiled CSS output with this tool.
There is no hard limit, but performance is best for files under 5 MB. Very large stylesheets may take a few seconds to process depending on your browser and hardware. For files exceeding 10 MB, consider splitting them into smaller partials.
By default, properties appear in their original order. Alphabetical sorting is available as an optional toggle in the toolbar. Some teams prefer alphabetical order for consistency and easier scanning; others prefer grouping related properties together (e.g., positioning, box model, typography). Choose the approach that matches your team's conventions.
The tool expects standalone CSS input. To format inline styles, extract the CSS from your HTML <style> tags, format it here, then paste it back. Alternatively, use the HTML Formatter which handles embedded styles automatically and formats the CSS within <style> blocks using the same formatting engine. This saves you the extra step of extracting and re-inserting the CSS manually.
The CSS Formatter adds whitespace for readability, while the CSS Minifier removes whitespace to reduce file size. They are complementary — format for development, minify for production.
Yes. Once the page has loaded, all formatting happens locally. You can disconnect from the internet and continue working without interruption.
Yes. CSS custom properties (--my-color: #333;) and var() references are fully supported and formatted correctly. The formatter also handles complex var() expressions with fallback values, such as var(--primary, var(--fallback, blue)), preserving the nesting structure.