Hoppscotch is an open-source API development ecosystem that helps you create and test your API requests saving precious time in development.

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

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.

Design, debug, and test APIs locally or in the cloud

Burp or Burp Suite is a set of tools used for penetration testing of web applications. It is developed by a company named Portswigger who make freely available a Web Security Academy which has a range of lessons on penetration testing.

HyperTest is a no-code test automation tool that regresses all your APIs by auto-generating integration tests using your network traffic, also giving a way to reproduce these failures inside actual user-journeys.