HTTP Archive : The HTTP Archive tracks how the Web is built.
Pact : Fast, easy and reliable testing for integrating web apps, APIs and microservices. Pact is a code-first tool for testing HTTP and message integrations ...
patchbay : patchbay.pub is a free web service you can use to implement things like static site hosting, file sharing, cross-platform notifications, webhooks hand...
httpbin.org : A simple HTTP Request & Response Service.
htty : htty is a console application for interacting with web servers. It’s a fun way to explore web APIs and to learn the ins and outs of HTTP.