Free CSS Validator Online
Validate CSS syntax and check for common errors.
Key Features
✅ Instant Validation
Validate CSS syntax instantly with real-time feedback as you type.
🔍 Syntax Checks
Detect unbalanced braces, invalid properties, and malformed rules.
⚡ Fast Processing
All operations run locally in your browser for instant results.
🔒 Privacy Protected
Your data never leaves your browser. No server storage.
How to Use CSS Validator
Paste Your CSS Code
Enter or paste your CSS code into the input area.
Click Validate
Press the "Validate" button or let the tool auto-validate as you type.
View the Result
See validation results with error details and warnings in the output area.
Frequently Asked Questions
Basics
What is CSS validation?
CSS validation is the process of checking whether CSS code follows proper syntax rules, including correct property-value pairs, balanced braces, and valid selectors.
Why should I validate CSS?
Valid CSS ensures consistent styling across browsers, reduces rendering issues, and makes your code easier to maintain and debug.
Common Errors
What are common CSS errors?
Common CSS errors include: missing semicolons, unbalanced braces, invalid property names, missing colons between property and value, and malformed selectors.
Does CSS support custom properties?
Yes, CSS custom properties (variables) use the -- prefix and are accessed with var(). They are valid in modern browsers.