BBuildQuill
Developer Tools

CSS Validator

Validate CSS syntax and find common errors. Check for unmatched braces, missing semicolons, and more.

How to use the CSS Validator

1

Paste your CSS

Copy and paste your CSS stylesheet into the input area.

2

Click Validate

Click the Validate button to scan for syntax issues.

3

Review issues

Errors and warnings are listed with line numbers. Fix them in your code.

About the CSS Validator Tool

Validate CSS syntax and find common errors. Check for unmatched braces, missing semicolons, and more. This free online css validator from BuildQuill runs entirely in your browser. No data is sent to any server, keeping your information private. No signup or installation needed.

  • Free to use with no account required
  • Works in all modern browsers
  • All processing happens locally in your browser
  • Part of BuildQuill's developer tools collection

Frequently Asked Questions

What does the CSS Validator check?
It checks for unmatched braces, missing semicolons, unterminated strings and comments, and empty rules. It is a syntax-level check, not a full W3C validation.
Can it validate SCSS or LESS?
This tool validates standard CSS syntax. SCSS nesting and LESS variables use different syntax rules and may produce false positives.
Does it fix errors automatically?
No. It reports issues with line numbers so you can fix them yourself. For auto-formatting, use the CSS Beautifier tool.

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