Request Runner is a free Chrome extension designed to enhance API testing directly within Chrome DevTools. It offers a comprehensive suite of features, enabling users to execute, inspect, and manage API requests without switching between multiple applications. Key functionalities include full HTTP support for various request types, request customization, code generation for different programming environments, and the ability to manage environment variables effectively.

This tool is particularly beneficial for developers and QA engineers, allowing them to save and replay previous requests, analyze responses, and visualize complex JSON structures. With features like request history, response diffing, and organizational capabilities through collections and folders, Request Runner simplifies the API testing process. The free tier provides essential functionalities, while pro features offer expanded capabilities for more intensive testing needs.