HttpMaster - HttpMaster is a professional software tool for testing and debugging HTTP applications, primarily aimed at REST API applications and web services.
Request inspector - Debug web hooks, http clients
API Fortress - API performance, accuracy, and uptime testing. Without code.
MockServer - Easy mocking of any system you integrate with via HTTP or HTTPS.
Hoppscotch - Open source API development ecosystem
CurlHub.io - API Traffic Inspector