HttpRequester
Postman
HTTPie
soapUI
Fiddler
HttpWatch
Advanced REST Client (ARC)
Insomnia REST
HTTP Headertool
Live HTTP Headers
HTTP Debugger
HTTP Header Live
ViewHTTPHeaders.com
Fiddler
HTTP Toolkit
Charles Proxy
Postman - The Collaboration Platform for API Development
Live HTTP Headers - The goal of this project is to adds information about the HTTP headers in three ways:
HTTPie - CLI HTTP that will make you smile. JSON support, syntax highlighting, wget-like downloads, extensions, and more.
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!
soapUI - SoapUI Pro is one of the most prominent API testing platforms around, allowing developers to quickly prototype the functions of their apps and get them to market with little hassle.
HTTP Header Live - Displays the HTTP header. Edit it and send it.