Jest is a delightful JavaScript Testing Framework with a focus on simplicity.

API Testing Platform that automatically generates unit test cases with dependency mocks from API calls

REST API client library for .NET

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.

Free & OpenSource REST API Testing Tool for all levels in a Test Pyramid

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.