View Rendered Source is a lightweight Chrome extension that allows web developers and SEOs to see how a browser renders a page, including modifications made by JavaScript. It provides three sections: Raw, Rendered, and Difference, highlighting the differences between the original HTML and the rendered version. This extension is particularly useful for developers using JavaScript frameworks like Angular, ReactJS, and Vue.js, as well as for SEOs to understand how search engines view a webpage. Additionally, it offers features for adaptive websites and dynamic serving for Google.