Postman is an API platform for building and using APIs. Postman simplifies each step of the API lifecycle and streamlines collaboration so you can create better APIs—faster.

Requestly is an open-source tool that simplifies API development, testing, mocking, and integration for developers and QAs.

Built for developers and testers alike, SoapUI is the only open source tool that covers the entire testing spectrum (functional, security, load, mocking).

Fully integrated API and web service testing capabilities that automate end-to-end functional API testing.

One test framework, for ALL your apps Maestro is a single platform that tests all of your mobile and web apps - no matter what framework your team uses.

RapidAPI for Mac is a full-featured HTTP client that lets you test and describe the APIs you build or consume. It has a beautiful native macOS interface to compose requests, inspect server responses, generate client code and export API definitions.