Markup Validator is a free Chrome extension developed by Roman Grinyov. It falls under the category of Browsers, specifically Add-ons & Tools. This extension allows users to check the markup of the current page or any HTML code.

With Markup Validator, users can easily validate the HTML code of a web page to ensure that it adheres to the correct syntax and standards. The extension offers the ability to check the markup using different markup validators, providing users with a comprehensive validation process.

The extension is user-friendly and accessible, making it easy for both beginners and experienced developers to utilize. By identifying any markup errors or issues, Markup Validator helps users maintain the quality and integrity of their web pages.

Overall, Markup Validator is a valuable tool for web developers and designers who need to ensure the accuracy and validity of their HTML code and page markup.