Web Developer Tools are software applications that help developers create, test, and debug websites and web applications. These tools provide features like inspecting HTML and CSS elements, monitoring network activity, and testing JavaScript performance. They are essential for ensuring that websites function correctly across different browsers and devices. Most modern web browsers, such as Google Chrome and Mozilla Firefox, come with built-in developer tools. These tools allow developers to view and edit the source code in real-time, making it easier to identify and fix issues. Overall, web developer tools enhance the efficiency and effectiveness of the web development process.