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.

Playwright enables reliable end-to-end testing for modern web apps.

Mockoon is the easiest and quickest way to design and run mock REST APIs.

Browser and Mobile Automation Test Framework for Node.js

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.

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