Modify Header Value (HTTP Headers) - Modify Header Value (HTTP Headers) is a browser extension that allows you to add, modify or remove a header for any request to your preferred domains.
Google Chrome Developer Tools - Get started with Google Chrome's built-in web developer tools.
WebSniffer - WebSniffer is an online tool to outlook HTTP request and response headers.
Firefox Developer Tools - Examine, edit, and debug HTML, CSS, and JavaScript on the desktop and on mobile.
Live HTTP Headers - The goal of this project is to adds information about the HTTP headers in three ways:
Postman - The Collaboration Platform for API Development