URL Toggle is a free Chrome extension developed by Don Patterson. It falls under the category of Browsers and specifically the subcategory of Add-ons & Tools. This handy extension allows users to toggle between sites that share URL pieces.

With URL Toggle, you can store a list of regular expression patterns and replacements. When a match is detected, you can quickly switch to a related site with just one click. For example, let's say you have a pattern and replacement set up for GitHub Pages sites. When you're on a hosted GitHub Pages site, the URL Toggle icon will become enabled and allow you to navigate to the corresponding GitHub repository effortlessly.

You have the freedom to add as many patterns and replacements as you need, making URL Toggle a versatile tool for managing your web browsing experience. Whether you frequently switch between related sites or simply want to streamline your navigation, URL Toggle provides a convenient solution.