Postman - The Collaboration Platform for API Development
HTTP Debugger - Debug HTTP API calls to a back-end and between back-ends. Easy of use, clean UI, and short ramp-up time. Not a proxy, no network issues!
Insomnia REST - The most intuitive cross-platform REST API Client ð´
Google Chrome Developer Tools - Get started with Google Chrome's built-in web developer tools.
soapUI - SoapUI Pro is one of the most prominent API testing platforms around, allowing developers to quickly prototype the functions of their apps and get them to market with little hassle.
Firefox Developer Tools - Examine, edit, and debug HTML, CSS, and JavaScript on the desktop and on mobile.