ViewHTTPHeaders.com - View HTTP header response for any web page.
HTTP-TRACKER - HTTP-TRACKER is an advanced browser extension that allows you to examine HTTP request headers, cookies, response Headers, website data, cookies and modify request headers before sending them.
HTTP Header Live - Displays the HTTP header. Edit it and send it.
Sky Live HTTP Headers - Sky Live HTTP Headers is an open-source browser extension that visually displays HTTP requests and response headers from every website you visit.
HTTP Debugger - Debug HTTP API calls to a back-end and between back-ends. Easy of use, clean UI, and short ramp-up time. Not a proxy, no network issues!
HTTP Header Analyzer - HTTP Header Analyzer is an open-source browser extension that allows you to see and analyze the current HTTP request and response header from the website URL.