REST API Testing is open-source web automation testing technique that is used for testing RESTful APIs for web applications. The purpose of rest API testing is to record the response of rest API by sending various HTTP/S requests to check if rest API is working fine or not. Rest API testing is done by GET, POST, PUT and DELETE methods.
SOAP UI is the leading open source cross-platform API Testing tool. SOAP UI allows testers to execute automated functional, regression, compliance, and load tests on different Web API. SOAP UI supports all the standard protocols and technologies to test all kinds of API’s. SOAP UI interface is simple that enables both technical and non-technical users to use seamlessly.
Postman is a standalone software testing API (Application Programming Interface) platform to build, test, design, modify, and document APIs. It is a simple Graphic User Interface for sending and viewing HTTP requests and responses. While using Postman, for testing purposes, one doesn’t need to write any HTTP client network code. Instead, we build test suites called collections and let Postman interact with the API. In this tool, nearly any functionality that any developer may need is embedded. This tool has the ability to make various types of HTTP requests like GET, POST, PUT, PATCH, and convert the API to code for languages like JavaScript and Python.