ModHeader is a popular Chrome extension that allows users to easily modify HTTP request and response headers, as well as redirect URLs. With ModHeader, you can add, modify, and remove headers, including commonly used ones like X-Forwarded-For, Authorization, Access-Control-Allow-Origin, and Content-Security-Policy. The extension also provides advanced features such as modifying cookies, an advanced Content-Security-Policy editor, and the ability to enable header modification by specific URLs.

One of the standout features of ModHeader is its user-friendly interface, which allows for quick and efficient header modification with just a few clicks. The extension also offers convenient features like the ability to add comments to headers, one-click "undo" functionality, and support for multiple profiles for easy switching. Additionally, ModHeader supports exporting and importing profiles, making it easy to share your configurations with others.

ModHeader is free to use, with the option to upgrade to a paid version for additional features. It is compatible with Chrome, Firefox, Edge, and Opera, and has a large user base of over 800,000 users on the Chrome Web Store. Whether you're a developer looking to test HTTP headers or a user looking to customize your browsing experience, ModHeader is a reliable and powerful tool.