CSS Validator
Validate CSS stylesheets for syntax errors, deprecated rules, and performance issues. Check for browser compatibility, optimize selectors, and ensure best practices. Perfect for front-end developers and designers.
CSS Best Practices Guide
✓ Best Practices
- • Use CSS custom properties (variables)
- • Keep selectors simple and specific
- • Group related styles together
- • Use shorthand properties when possible
- • Minimize use of !important
- • Use meaningful class names
- • Optimize for performance
- • Include vendor prefixes for new features
- • Use media queries for responsive design
- • Comment your code for clarity
✗ Common Mistakes
- • Overly complex selectors
- • Missing vendor prefixes
- • Using deprecated properties
- • Duplicate or redundant rules
- • Missing units on numeric values
- • Invalid color values
- • Unclosed braces or syntax errors
- • Overusing performance-heavy properties
- • Poor specificity management
- • Inconsistent naming conventions
Sample CSS Code
About CSS Validator
A comprehensive CSS validation tool that analyzes stylesheets for syntax errors, deprecated properties, browser compatibility issues, and performance problems. This validator ensures your CSS follows current standards, identifies potential conflicts, and suggests optimizations for better rendering performance.
Why use a CSS Validator?
Clean, valid CSS is essential for consistent styling across browsers, optimal page load times, and maintainable code. This validator helps identify problematic rules, deprecated properties, and performance bottlenecks before they cause styling issues or slow down your website, ensuring professional-quality frontend development.
Who is it for?
Crucial for frontend developers writing custom styles, web designers ensuring cross-browser compatibility, UI/UX professionals optimizing design systems, and teams maintaining large CSS codebases. Perfect for anyone who wants to ensure their stylesheets are efficient, valid, and future-proof.
How to use the tool
- Input your CSS code directly or upload a stylesheet file
- Run the validation to check for syntax errors and compliance issues
- Review detailed reports on deprecated properties and browser compatibility
- Analyze performance suggestions and optimization recommendations
- Apply fixes and re-validate to ensure your CSS meets current standards
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