Postman is the complete toolchain for API developers, used by more than 3 million developers and 30000 companies worldwide. Developed by Postdot Technologies, Inc.
License: Freemium
SoapUI is an open-source web service testing application for service-oriented architectures (SOA) and representational state transfers (REST). Its functionality includes web service inspection, invoking, development, simulation and mocking, functional testing, load and compliance testing. Developed by SmartBear Software
License: Open Source
Postman excels in its user-friendly interface and strong support for REST APIs, making it ideal for developers. In contrast, soapUI is focused on SOAP testing and offers advanced features for complex API testing scenarios, though it comes with a steeper learning curve.