What is SoapUI? API Testing for SOAP and REST

What is SoapUI?

SoapUI is an API testing tool from SmartBear for SOAP and REST services. SoapUI Open Source supports REST, SOAP, GraphQL and JMS, and lets you build functional tests, assertions and mock services in a desktop application. ReadyAPI is SmartBear’s commercial platform for teams that also need performance and security testing.

SoapUI Open Source vs ReadyAPI

SmartBear describes SoapUI Open Source as the simplest way to start API testing, for individuals working on one machine in one environment. ReadyAPI is positioned for teams working across several environments and adds more protocols, such as XML-RPC and MQTT. SmartBear also owns Swagger, the tooling around the OpenAPI specification, and SoapUI supports Swagger and OpenAPI definitions as well as WSDL files.

How SoapUI works

• Import a WSDL or an OpenAPI definition, and SoapUI generates requests for each operation.
• Group requests into test steps, test cases and test suites, then add assertions on status, content or response time.
• Feed test data from files or a database, and use scripting for logic that point-and-click steps cannot express.
• Create SOAP or REST mock services so a client can be developed before the real service exists, see API mocking.
• Run suites from the command line so a CI server can execute them.

Example: testing a SOAP order service

Import the service WSDL, create a request for the GetOrder operation and send it. Add an assertion that the response is valid and contains the expected order status, then parameterize the order id from a data file. Saved as a test case, the check can run on every build as part of API testing.

Common mistakes with SoapUI

• Asserting only the HTTP status. The body can still hold an error or wrong data, so assert on the content.
• Hard-coding endpoints and credentials instead of using properties per environment.
• Keeping tests only on one laptop. Store the project in version control and run it from the command line in CI.
• Treating a desktop run with a few threads as a load test. Realistic load needs many concurrent users from outside your network.
• Never re-checking the live service. Passing tests prove a build, not that production is up.

SoapUI, JMeter and monitoring

SoapUI checks that an API answers correctly. For load, JMeter is the common open-source choice, and LoadFocus can run JMeter scripts in the cloud, see JMeter load testing and the guide to load testing REST APIs with LoadFocus. For checks after release, API monitoring calls your endpoints on a schedule, see API monitoring with LoadFocus. LoadFocus does not integrate with SoapUI or import SoapUI projects.

FAQ

Is SoapUI free?

SoapUI Open Source is free. ReadyAPI is a paid SmartBear product with more features for teams.

Is SoapUI still maintained?

SmartBear still publishes SoapUI on soapui.org, with a releases page and a 2026 copyright notice. Check that page for the current version and status.

Can SoapUI test REST APIs or only SOAP?

Both. SoapUI Open Source supports REST, SOAP, GraphQL and JMS.

What is the difference between SoapUI and ReadyAPI?

SoapUI Open Source is for individuals starting out with API testing. ReadyAPI is the commercial platform for teams, with additional protocols and performance and security testing.

Does SoapUI replace load testing tools?

No. It is built for functional API tests. For realistic load from many users, use a load testing tool such as JMeter.