Resource Override is a powerful Firefox extension designed for web development and IT professionals. This subscription-based tool provides users with the ability to gain full control over any website by enabling redirection of traffic, editing, and inserting new content. Among its key features are the modification of request and response headers with commonly used presets, which facilitate tasks like enabling CORS and allowing iframes.

The extension allows users to redirect URLs in real-time before requests are executed. It is also capable of redirecting URLs to custom text documents created within the extension. Additionally, it supports the injection of JavaScript and CSS files, making it an invaluable resource for debugging production websites. By allowing users to edit and inject code on the fly, Resource Override simplifies the process of working with minified code, providing a more efficient workflow.