Testing and validating REST services in Java is harder than in dynamic languages such as Ruby and Groovy. REST Assured brings the simplicity of using these languages into the Java domain.

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

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

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

Get control of your alerts, crash reports and security notifications with duplication removal, noise suppression and our neural network powered grouping.

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.