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.

Automate front-end software testing with a single sentence.

Built by testers, for testers - TestGear is a TMS that truly unites manual and automated testing, adapts to any testing framework, and is designed for flexibility, clarity, and collaboration to improve team performance and release better software, faster.

Puppeteer is a Node.js library which provides a high-level API to control Chrome/Chromium over the DevTools Protocol.

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