Page Info is a Chrome extension developed by Akinori Musha. It is a free extension in the Browsers category, specifically under Add-ons & Tools. This extension provides users with a variety of features to check and gather information about the web pages they are viewing.

One of the main features of Page Info is the Canonical URL Checker. When a web page is loaded, the extension checks if the URL is canonical and changes its icon face accordingly. Additionally, users can quickly access the canonical URL of the current page using a shortcut key.

Another useful feature is the Page Information Viewer. By clicking on the extension icon, a popup window appears where users can find information such as the canonical URL, site name, site icon, image, page title, and Twitter equivalents. The extension also allows users to copy the link to the page as Markdown.

Page Info also offers a customizable Save URL button that can be added to the popup window. This button allows users to bookmark the current page online with popular services like Raindrop, Pocket, Pinboard, and Inoreader.

Furthermore, the extension provides context menu items to copy any link or image as Markdown. This feature is particularly useful for users who want to paste links into WYSIWYG editors, Slack, Google Docs, and more.

Overall, Page Info is a simple and unobtrusive Chrome extension that serves as a utility for daily browsing. It provides users with easy access to page information, canonical URL checking, and various options for saving and copying URLs.