Outliner is a free Chrome extension developed by Zach Baker. It falls under the category of Browsers and specifically the subcategory of Add-ons & Tools. As the name suggests, Outliner is designed to outline all the DOM elements on a web page.

With Outliner, users can easily visualize the boundaries of DOM elements by displaying dashed outlines around them. This can be particularly useful for web developers and designers who need to inspect and understand the structure of a webpage. By clearly outlining each element, Outliner allows users to quickly identify and analyze the layout and hierarchy of a page's content.

The extension provides a simple and straightforward way to expose DOM element boundaries, making it easier to debug and troubleshoot any layout issues. Whether you're a seasoned developer or just curious about how a webpage is structured, Outliner offers a convenient tool for visualizing the DOM elements on any page you visit.

Please note that Outliner is available exclusively for the Chrome browser, providing a seamless integration with your browsing experience.