Fast, easy and reliable testing for anything that runs in a browser, Cypress is the new standard in front-end testing that every developer and QA engineer needs.

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

Next-gen browser to build, test & debug mobile websites.

ReadyAPI is a low-code API testing platform for development teams that care about creating test automation across any workflow.

REST API client library for .NET

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.