Outline All Elements is a free Chrome extension developed by MohannadNaj. It falls under the category of Browsers and is specifically categorized as an Add-ons & Tools subcategory. This extension allows users to add the CSS Outline property to all elements on a webpage for the purpose of debugging CSS layout.

By clicking on the extension icon, users can activate or deactivate the functionality of the extension. When activated, the extension adds the CSS Outline property to all elements on the page with different colors. The colors are randomized based on the order of the elements on the page. This helps in easily identifying and visualizing the layout of the webpage and discovering potential CSS layout issues.

One notable feature of Outline All Elements is that it restores the old outline value if it was present before activating the extension. If the outline style was not present, the extension removes the style HTML attribute upon deactivation.

Overall, Outline All Elements is a useful tool for web developers and designers who want to quickly identify and debug CSS layout issues. It provides a simple and efficient way to visualize the layout of webpages and discover potential problems.