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.

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

Swagger UI allows anyone — be it your development team or your end consumers — to visualize and interact with the API’s resources without having any of the implementation logic in place

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

Sonic is a platform that integrates remote control debugging and automated testing of mobile devices, and strives to create a better user experience for global developers and test engineers.

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