Website Tools
CSS Validator
Check a webpage's CSS (inline and linked stylesheets) for common syntax issues.
Enter a URL below to check its inline and linked CSS for common syntax issues.
JustChecker tracks your website's health continuously, catching problems before they affect your visitors.
Frequently Asked Questions
It checks a page's inline <style> blocks and up to 3 linked stylesheets for unbalanced braces, empty rule blocks, duplicate selectors, and a small set of deprecated or non-standard properties.
This keeps the check fast and lightweight for everyone using the free tool. Most pages have their most important styling in the first few stylesheets loaded.
Not necessarily - repeated selectors are sometimes intentional (e.g. for media queries). But unintentional duplicates are a common source of confusing, hard-to-debug styling conflicts, so this tool flags them for your review.