mitmproxy : mitmproxy is your swiss-army knife for debugging, testing, privacy measurements, and penetration testing. It can be used to intercept, inspect, modify...
httpbin.org : A simple HTTP Request & Response Service.
Zombie.js : Zombie.js is a lightweight framework for testing client-side JavaScript code in a simulated environment. No browser required.
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...
Security Headers : I built securityheaders.io after deploying security headers like CSP and HSTS to my own site. I wanted a quick and easy way to check if other sites we...
toxy is a fully programmatic and hackable HTTP proxy to simulate server failure scenarios and unexpected network conditions, built for node.js/io.js.