Selenium automates browsers. That's it! What you do with that power is entirely up to you.

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

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

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

Unifying API testing, API Performance testing, API Mocks and UI testing.

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