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

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

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

HyperTest is a no-code test automation tool that regresses all your APIs by auto-generating integration tests using your network traffic, also giving a way to reproduce these failures inside actual user-journeys.

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

Bruno is a Fast and Git-Friendly Opensource API client, aimed at revolutionizing the status quo represented by Postman, Insomnia and similar tools out there.