Wireshark : Wireshark is the world's foremost network protocol analyzer. It lets you see what's happening on your network at a microscopic level. It is the de fac...
GoReplay : GoReplay is an open-source tool for capturing and replaying live HTTP traffic into a test environment in order to continuously test your system with r...
toxy : toxy is a fully programmatic and hackable HTTP proxy to simulate server failure scenarios and unexpected network conditions, built for node.js/io.js.
httpbin : Testing an HTTP Library can become difficult sometimes. PostBin.org is fantastic for testing POST requests, but not much else. This exists to cover al...
An HTTP Viewer and HTTP Sniffer for IE and Firefox