Testing Web Service or APIs (Application Programming Interface) are the connectors that enable servers and applications to communicate with each other to complete a transaction or progression. Although, behind every bank transaction or ticket booking process, web services gather the information divided over many critical servers, applications, or various platforms.

Testing Web Service includes:

  • Determining the response and request format of XML.
  • Sending requests and validating the response.

There are many open-source web service testing tools available in the software market. Although these tools’ core functionalities are similar, they differ in their usability and interoperability.

Here is a list of top web services testing API tools. 

  1. SoapUI
  2. TestingWhiz
  3. SOAPSonar
  4. SOAtest
  5. HTTPMater
  6. Postman
  7. vRest
  8. Storm


SoapUI is an open-source and free web services testing tool. You can use this tool to test SOAP web services, RESTful Web Services, or HTTP based services. Its interface is so simple that both technical and non-technical users can easily use it. A good thing about it is it supports all the standard protocols and technologies. 


  • Inspection
  • Development
  • Simulation and mocking
  • Invoking
  • Functional, compliance, and security testing 


It is a codeless test automation tool used for regression and database. It can perform end-to-end testing, such as Bid data, Meta Data, Web UI, Cross Browser testing & Distributed Execution for Web, which deal with cloud-based and mobile applications. This tool is based on a robust architecture combined with the short learning curve and Automation Engine.


  • FAST Automation Engine
  • Object Eye Internal Recorder
  • Visual Recorder
  • Integrated Mobile Recorder
  • Integrated OCR Capability using Google Vision API and Tesseract
  • Integrated Python Editor
  • Integrated PDF and Excel Commands
  • Export Reports to PDF
  • SVN Integration
  • Centralized Object Repository
  • Pattern-based Data Comparison
  • Merge Different Test Projects
  • Multiple Browsers Support
  • 300+ Commands
  • Dynamic Test Data Support
  • Continuous Server Integration
  • Reusable Methods


It provides comprehensive web services for XML, HTML, REST, SOAP, and JSON that rapidly test the web services. SoapSonar also provides functional, performance, interoperability, and security testing with out-of-the-box support for W3C and OASIS standards.


  • It gives reports in XML, PDF, RTF, DOC, and RPT formats.
  • It performs load testing with behaviour forming and multiple simultaneous loading dealings.
  • This tool is machine-independent, sends requests, and receives responses directly.
  • It supports vulnerability tests with XSD-mutation.
testing web service


SOAtest is a grading tool used for testing and validating APIs and API-driven apps. This tool provides strong support for the functional unit, integration, simulation, compliance, and load testing of technologies like JSON, HTTP, XML, MQ, REST, TIBCO, and JMS.


  • It includes support of 120+ protocols/ message types.
  • It offers end-to-end testing.
  • It helps to create sophisticated, reusable, and extensible tests without coding.
  • It provides an easy to use interface.


HTTPMaster is a web development and testing tool for REST web services and API applications. Testers use it to test and validate the most common REST format like XML, HTML, and JSON. This tool also supports dynamic parameters, which we can use to simulate input data variations or for global reuse values creation through multiple requests. 


  • API Testing
  • Has feature Web Services Testing
  • Has feature Website Testing
  • It utilizes CLI (Command Line Interface) for test creation and execution.
  • Allows storing all information-API calls and project data in a single place.


It is another API/ testing Web service tool that links with powerful HTTP client support. It has an easy request generator that allows you to write test cases and manage response data and RT (response time) to manage API test cases.


  • Comes text pasting feature for hassle-free creation on CLW (command line window).
  • Allows writing Boolean tests in Postman Interface.
  • It facilitates sharing of API data and controls with the team.


This tool is for mocking, testing, and validating REST APIs and web services. This extension helps record HTTP requests of the web application under test. After recording requests, it records and automatically stores parameters, headers, and responses as a test case in vRest. 


  • Has a mock server functionality to create API mock.
  • Provides a chrome extension to playtest cases.


It is an open-sourced testing tool. You can use it for testing web services written in Java or .Net. 

Most of the time, it is in F# language. 


  • It allows testing multiple web services from a single UI.
  • It supports the testing of WCF apps.
  • It will enable invoking a web service method that contains complex data types.

There are several other testing tools too. This list does not end here. 

There are several Web Services-test-automation frameworks available that are productive. You can utilize these testing web service tools for more evaluation, functionality, and scalability.