Built for developers and testers alike, SoapUI is the only open source tool that covers the entire testing spectrum (functional, security, load, mocking).

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

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

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

NUnit is a unit-testing framework for all .Net languages.

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