Validator.w3.org
The W3C Markup Validation Service
Check your website’s HTML or XHTML for errors and standards compliance with this easy-to-use markup validation service from the World Wide Web Consortium.
Validate your website's HTML for standards compliance
The W3C Markup Validation Service lets you check your website's HTML or XHTML for errors and ensure it meets web standards. You simply enter a web address or upload your file, and the tool quickly scans your code for any issues that might affect your site's performance or accessibility.
Whether you're a web developer, designer, or just curious about your site's code quality, this validator makes it easy to spot mistakes and learn how to fix them. It's a trusted resource from the World Wide Web Consortium (W3C), supporting a wide range of markup languages and offering helpful feedback to improve your site's reliability and compatibility.
If you want your website to work smoothly across browsers and follow best practices, this service is a straightforward way to keep your code in top shape.
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