The AMP Validator is a free Chrome add-on developed by amphtml-validator-extensions. It automatically checks each page for AMP (Accelerated Mobile Pages) validation.

Upon visiting a webpage, the AMP Validator determines if it is an AMP page and then runs it through the AMP validator. The extension icon displays a green color if the page passes the validation, indicating that it is AMP-compliant. Conversely, if the page fails the validation, the icon turns red.

In case of any warnings or errors, the extension icon shows the corresponding number, and clicking on the icon reveals a detailed list of warnings and errors. This allows users to quickly identify and address any issues with their AMP pages.

Additionally, if the current page is not an AMP page but an AMP version is available via the `` tag, the extension icon turns blue. Clicking on the icon loads the AMP version of the page, providing a seamless browsing experience.