CSS Formatter

Format and validate CSS code with syntax highlighting

Overview

A powerful online CSS formatter and beautifier that helps you format, optimize, and clean up CSS code. This tool supports modern CSS features, including flexbox, grid, and custom properties, while providing real-time validation and syntax highlighting for optimal code readability.

Key Benefits

  • Instant CSS formatting with customizable indentation
  • Support for modern CSS features and syntax
  • Real-time syntax validation and error detection
  • Vendor prefix normalization
  • Property sorting and grouping options
  • Cross-browser compatibility checks
  • Copy formatted CSS with a single click

Primary Use Cases

  • Cleaning up minified CSS code
  • Standardizing CSS coding style
  • Preparing CSS for code reviews
  • Formatting CSS for documentation

Features

Main Features

  • Real-time CSS validation and formatting
  • Customizable indentation (2-8 spaces)
  • Property sorting and grouping
  • Vendor prefix handling
  • Error highlighting with detailed messages
  • Support for modern CSS features
  • Dark mode support

Technical Specifications

  • Handles CSS files up to 10MB
  • Supports CSS3+ features
  • Preserves valid CSS comments
  • Maintains @media query structure
  • Compatible with CSS modules syntax

How It Works

The CSS formatter uses a sophisticated parsing and formatting engine to process your CSS code. It first validates the input to ensure it's valid CSS, then applies formatting rules and optimizations to create clean, consistent output.

Steps

  1. Paste or upload your CSS code into the input field
  2. The tool automatically validates the CSS syntax
  3. Formatting rules are applied in real-time
  4. Properties are sorted and grouped (if enabled)
  5. Vendor prefixes are normalized
  6. The formatted output appears with syntax highlighting

Limitations

  • Maximum file size: 10MB
  • Some CSS hacks may be altered
  • Custom property ordering may be affected

Examples

Basic CSS Formatting

Example of formatting a simple CSS rule set

Input:

.container{display:flex;flex-direction:column;padding:20px;background-color:#f5f5f5;border-radius:4px}

Output:

.container {
  display: flex;
  flex-direction: column;
  padding: 20px;
  background-color: #f5f5f5;
  border-radius: 4px;
}

Complex CSS with Media Queries

Formatting CSS with media queries and nested selectors

Input:

@media screen and (max-width:768px){.header{flex-direction:column;}.nav{padding:10px;display:flex;gap:1rem;}.nav-item{color:#333;text-decoration:none;}}

Output:

@media screen and (max-width: 768px) {
  .header {
    flex-direction: column;
  }

  .nav {
    padding: 10px;
    display: flex;
    gap: 1rem;
  }

  .nav-item {
    color: #333;
    text-decoration: none;
  }
}

Frequently Asked Questions

What is CSS formatting?

CSS formatting is the process of organizing CSS code with proper indentation, spacing, and line breaks to improve readability while maintaining its functionality.

Does formatting affect my CSS functionality?

No, formatting only changes the presentation of your CSS code. The styling behavior and functionality remain exactly the same.

Can I format minified CSS?

Yes, you can paste minified CSS and the formatter will add proper spacing, indentation, and line breaks to make it readable.

Does it support modern CSS features?

Yes, the formatter fully supports modern CSS features including flexbox, grid, custom properties, and other CSS3+ syntax.

Tips & Best Practices

Best Practices

  • Use consistent property ordering
  • Group related properties together
  • Maintain a consistent naming convention
  • Use comments to document complex selectors
  • Keep selectors as simple as possible

Common Pitfalls

  • Not validating CSS before deployment
  • Mixing different naming conventions
  • Overusing !important declarations
  • Creating overly specific selectors
  • Ignoring browser compatibility

Technical Details

Supported Formats

  • Standard CSS
  • CSS Modules
  • CSS-in-JS (cleaned)
  • Vendor-prefixed CSS
  • CSS Custom Properties

Limitations

  • Maximum file size: 10MB
  • Maximum selector depth: 50 levels
  • Maximum line length: 2000 characters

Browser Compatibility

  • Works in all modern browsers
  • Chrome 60+
  • Firefox 60+
  • Safari 12+
  • Edge 79+

Security & Privacy

Data Handling

  • All processing is done in your browser
  • No data is sent to servers
  • No data is stored or cached
  • Files are processed in memory only

Privacy Considerations

  • No cookies used for formatting
  • No tracking or analytics in the tool
  • No data collection of any kind
  • Open source code for transparency

Resources & References

Documentation

References