Following are the alternatives to the SoapUI for testing web services:
Like SoapUI, JMeter is also free and open source testing application. It is purely Java based and platform independent application. Primarily it was designed for web application testing. But it offers other testing as well like functional test, load test, regression test, stress test.
If you want to test web services without heavy weight SoapUI or JMeter, Postman is the solution. It is the most used REST client worldwide. Postman is available as a native app for Windows (X32, X64), Mac and Linux (X32, X64). You can download it from here. It has a Chrome browser plugin also. You can install it from Chrome web store.
My third pick as SoapUI alternative is Wizdler. If you don’t need all fancy features of SoapUI, try this one. Wizdler is a browser extension web service testing tool, comes with Google Chrome and Mozilla Firefox. Once you put the WSDL address in the webpage address bar, Wizdler recognizes it and lists down all available services and operations.
Primary focus of HttpMaster is to develop and test REST web services and web API applications. You can test SOAP web services also if methods are exposed via http. But it does not support advanced features like WSDL parsing to extract SOAP methods. It has nice, clear and well defined user interface. You can create project, add header and parameters quite easily without any advanced technical skill.