Free Online CSS Validator & Linting Tool
Validate and check your CSS stylesheets for syntax errors, unclosed braces, bad property declarations, and structural mistakes instantly. 100% free and runs directly in your browser.
Key Features of Our Online CSS Validator
Real-Time Error Detection
Find unclosed brackets, missing semicolons, and invalid property-value pairs as you type.
Detailed Line-by-Line Reporting
Get clear error messages with exact line numbers so you can fix issues quickly.
CSS Stats & Breakdown
View total selector counts, rulesets, and code size metrics alongside error reports.
100% Client-Side & Private
Your code is never uploaded to any server. Everything is parsed locally in your browser.
How to Use the CSS Validator
- Paste your raw CSS code or stylesheet into the code editor area.
- Click on the "Validate CSS" button to run the syntax analysis.
- Review the generated error list and warning logs with line numbers.
- Fix the identified errors and copy your clean CSS code.
Frequently Asked Questions (FAQs)
Does this tool support CSS3 features?
Yes, it checks standard CSS3 properties, flexbox, grid, and media queries.
Is my CSS stored on a database?
No. All validation logic runs inside your browser using JavaScript parser algorithms.