8 Best SoapUI Alternatives for API Testing (2026)

SoapUI Open Source vs ReadyAPI: what you are replacing

SoapUI is SmartBear's desktop tool for functional API testing, best known for SOAP services: you load a WSDL, SoapUI generates the requests, and you add assertions, mock services, and test suites around them. It also handles REST, GraphQL, and JMS.

Today, SoapUI comes in two forms:

• SoapUI Open Source is still free and listed on soapui.org as the open source edition.
• ReadyAPI is SmartBear's paid product, which soapui.org calls its "next generation API testing solution." On soapui.org's comparison, ReadyAPI adds data-driven testing, native CI/CD plug-ins, Git storage, and security, performance, and virtualization testing.

That split explains most moves away from SoapUI. Teams outgrow the free edition when they need data-driven tests from files or databases, native CI/CD plug-ins instead of scripted command-line runs, or test reports beyond logs, and then have to choose between a ReadyAPI license and another tool. Other common reasons are a desktop UI that can feel heavy on large projects, Groovy scripting for anything beyond basic assertions, and APIs that have moved from SOAP to REST or GraphQL.

SoapUI alternatives at a glance (as of November 2026)

The table separates tools that work with SOAP and WSDL from REST-first tools. Prices come from each vendor's own site as of November 2026; Katalon Studio prices are on the Katalon pricing page.

Prices and plans change often. Check each vendor's pricing page before you buy.

1. Katalon Studio

Katalon Studio is a test automation tool for API, web, mobile, and Windows desktop testing (desktop on Professional and above). For API work it sends REST requests (GET, POST, PUT, PATCH, DELETE) and SOAP 1.1 and 1.2 requests, and it runs GraphQL queries as REST calls over GET or POST. See API testing with Katalon for an overview.

For SoapUI users, the import options are the main draw. Studio can bring in:

• Requests from a SoapUI project (REST and SOAP)
• SOAP requests from a WSDL
• REST requests from an OpenAPI 3.0 or Swagger 2.0 file
• Postman collections (v2.1)

Imported requests land in the Object Repository, where test cases reuse them. A typical test sends a request with a Web Service keyword, then verifies a response field with another keyword, without code. Engineers can switch to the script view and write Groovy or Java. The same test case can mix API steps with web or mobile steps, which helps when a UI flow depends on data an API creates.

Pros:

• SOAP and REST in one tool, with WSDL and SoapUI project import, so you don't rebuild requests by hand.
• Keyword steps for testers and Groovy or Java for engineers, on the same test case.
• API, web, and mobile tests in one project, plus Windows desktop tests on Professional and above.
• Data-driven testing with basic sources on every plan; database sources and data binding on Professional and above.

Cons:

• A desktop IDE is more than you need if you only send a few requests.
• The SoapUI import brings across REST and SOAP requests; plan to rebuild assertions and Groovy scripts with verification keywords or in the script view.
• GraphQL support is basic: queries run as REST calls, and the docs list GraphQL variables as not working yet.
• Command-line and CI/CD runs need the Katalon Runtime Engine (KRE) add-on and a paid plan (Professional or Enterprise). Windows desktop testing, parallel execution, and BDD (Cucumber) are Professional and above.

Best for: QA teams with a mix of SOAP and REST services who want API regression suites next to their UI tests.

Pricing (as of November 2026): a Free plan for local authoring and runs of web, API, and mobile tests, with up to 10 static test suites; Professional at $1,800 per seat per year (about $150 a month), billed annually; Enterprise custom. There is a 30-day free trial. KRE (for CI runs) and TestCloud (cloud browsers and devices for UI tests) are add-ons. See the Katalon pricing page.

2. ReadyAPI

ReadyAPI is SmartBear's commercial API testing suite and the paid successor to SoapUI. It is sold as separate products: API Functional Testing, Performance, Virtualization, and Parallel Testing (TestEngine), and SmartBear also lists an MCP server. Functional testing covers REST, SOAP, GraphQL, Kafka, JDBC, and JMS.

Pros: the most direct upgrade from SoapUI, with the same project model, plus data-driven tests, service virtualization, security scans, and CI plug-ins.

Cons: pricing is not published, and ReadyAPI is sold as separate modules, so a full suite means several licenses.

Best for: enterprise teams with large SOAP and REST estates that want to stay in the SmartBear ecosystem.

Pricing (as of November 2026): no list prices on smartbear.com ("customizable plans"); 14-day free trial. Website: ReadyAPI

3. Postman

Postman is an API platform for sending, testing, documenting, and sharing requests. Tests are written in JavaScript, and the Collection Runner and Postman CLI run collections locally and in CI. It can send SOAP requests as a POST with an XML envelope, but its SOAP tooling is lighter than SoapUI's. Postman can import data from SoapUI (as of November 2026), but it has no documented WSDL import, so SOAP requests are XML envelopes you maintain by hand.

Pros: a familiar interface, shared workspaces, documentation and mock servers, and a large community.

Cons: SOAP work means building envelopes by hand; the Free plan is for 1 user only; scripting is JavaScript only; no web, mobile, or desktop UI testing.

Best for: REST-first teams that explore and share APIs across developers and testers. For a full comparison, see SoapUI vs Postman.

Pricing (as of November 2026): Free (1 user); Solo $9 per month and Team $19 per user per month, both billed annually; Enterprise by quote. Website: Postman

4. Karate

Karate is an open source (MIT) framework for API tests, mocks, and performance tests, written in a readable Gherkin-style syntax. Most API checks need no Java step definitions, and tests run with standard Java build tools in CI. It can test SOAP services by posting XML and asserting on the response.

Pros: readable tests that live in Git, built-in JSON and XML assertions, HTML reports, and a free core.

Cons: no WSDL import, the Xplorer desktop client and IDE features beyond the basics are separate (some paid), and teams still need a Java toolchain.

Best for: engineering-minded QA teams that want code-light API tests in the same repo as the service.

Pricing (as of November 2026): core framework free; Xplorer free, Premium $200 per user per year; IDE Plus $100 and IDE Pro $640 per user per year; Enterprise custom. Website: Karate Labs

5. REST Assured

REST Assured is an open source (Apache 2.0) Java library for testing REST services. You write tests in a given, when, then style and run them with JUnit or TestNG, so they fit any Java build and CI pipeline. It validates JSON and XML responses, and it works with frameworks such as Serenity BDD.

The project is active: version 6.3.0 shipped on October 23, 2026, and the maintainers say 7.0.0 will drop Groovy and HttpClient 4 from the default dependencies.

Pros: full control in code, tests reviewed and versioned with the application, no license cost, and no vendor lock-in.

Cons: Java skills required, no GUI, no WSDL import or SOAP-specific tooling, and reporting depends on your test runner and plugins.

Best for: Java developers and SDETs who want REST API tests next to application code.

Pricing (as of November 2026): free. Website: REST Assured

6. Insomnia

Insomnia is Kong's open source (Apache 2.0) API client for REST, GraphQL, and gRPC. Projects can live locally, in the cloud, or in Git, and the Inso CLI runs collections and linting in CI.

Pros: a free Essentials plan, Git Sync, mock servers, and API design linting.

Cons: SOAP is not a listed focus, and its strength is debugging and design more than test management.

Best for: developers who work across REST, GraphQL, and gRPC and want a lighter desktop client than SoapUI.

Pricing (as of November 2026): Essentials free; Pro $12 per user per month and Enterprise $45 per user per month (self-serve up to 50 users), both billed annually. Website: Insomnia

7. Bruno

Bruno is an open source (MIT) API client that stores collections as plain text files on your machine, so they go into Git with your code. It works offline without an account and has a CLI for CI runs.

Pros: offline and Git-friendly by design, light to run, and a free open source edition.

Cons: Bruno lists HTTP, REST, GraphQL, and gRPC but not SOAP, and some team features are paid.

Best for: REST teams that want collections in Git and no cloud sync.

Pricing (as of November 2026): Open Source edition free; Pro $6, Ultimate $11, and Enterprise $18 per user per month, billed annually. Website: Bruno

8. Hoppscotch

Hoppscotch is an open source (MIT) API client that runs in the browser, as a desktop app, or self-hosted. It covers REST and GraphQL plus real-time protocols such as WebSocket.

Pros: fast, usable without an account, and self-hostable for teams with data rules.

Cons: no WSDL import or SOAP-specific tooling, and lighter test scripting than dedicated test tools.

Best for: quick REST and GraphQL requests in the browser, and teams that want to self-host their API client.

Pricing (as of November 2026): Free; Business $6 and Enterprise $11 per user per month, billed annually. Website: Hoppscotch

JMeter vs SoapUI: where JMeter fits (API load testing)

In JMeter vs SoapUI comparisons, JMeter solves a different problem. The Apache project describes it as built to load test functional behavior and measure performance. Use it when you need to put SOAP or REST endpoints under load, not as your functional API test tool. It is free and open source, and runs headless from the command line in CI.

A common pattern is a functional tool (Katalon Studio, ReadyAPI, Karate, or REST Assured) for correctness, plus JMeter for load.

How to migrate from SoapUI to Katalon Studio

If you have years of SoapUI projects, a migration path matters more than a feature list. In Katalon Studio:

1. Import the SoapUI project. Studio reads the project file and creates REST and SOAP request objects in the Object Repository.
2. Re-import WSDLs where you need fresh operations. Importing a WSDL generates SOAP requests for each operation.
3. Rebuild assertions. Katalon's docs cover importing requests, so plan to add verification keywords for status codes, response fields, and schemas, or port Groovy assertions to the script view.
4. Add test data. Bind requests to data files for data-driven runs (basic sources on every plan; databases and data binding on Professional and above).
5. Wire up CI. Run suites from the command line or in Jenkins, GitHub Actions, Azure DevOps, or GitLab with Katalon Runtime Engine on a paid plan.

Start with one service and a handful of tests, compare results with SoapUI, then move the rest.

Katalon Studio vs REST Assured

Teams that leave SoapUI often weigh a tool against a library. The trade-off is who writes and maintains the tests.

• Who writes tests: in Katalon Studio, testers build tests with keywords and engineers extend them in Groovy or Java. REST Assured tests are Java code, written by developers and SDETs.
• SOAP and imports: Katalon Studio sends SOAP 1.1 and 1.2 requests and imports SoapUI projects, WSDLs, OpenAPI files, and Postman collections. REST Assured focuses on REST, and requests are written in code.
• UI tests: Katalon Studio keeps API, web, and mobile tests, plus Windows desktop tests on Professional and above, in one project. REST Assured covers APIs only, so UI tests need another library such as Selenium.
• CI runs: Katalon Studio runs in pipelines through the Katalon Runtime Engine add-on on a paid plan. REST Assured runs in any Java build (Maven or Gradle) with JUnit or TestNG.
• Reports: Katalon Studio has built-in execution reports. REST Assured relies on your test runner and its plugins.
• Cost: Katalon Studio has a Free plan and Professional at $1,800 per seat per year, billed annually (pricing). REST Assured is free.

Choose REST Assured if your API tests belong in the service's repository and your team writes Java every day. Choose Katalon Studio if testers who don't code need to build and maintain API tests, if you still have SOAP services, or if API checks need to sit next to UI tests.

Is SoapUI still free?

Yes. SoapUI Open Source is still free to download from soapui.org as of November 2026. The paid product is ReadyAPI, which adds data-driven testing, native CI/CD plug-ins, Git storage, and security, performance, and virtualization testing. SmartBear doesn't publish ReadyAPI prices, and offers a 14-day trial.

How to choose a SoapUI alternative

1. Count your SOAP services. If WSDL-based services are a large part of your estate, shortlist tools with WSDL import (Katalon Studio, ReadyAPI). REST-only clients will mean hand-built envelopes.
2. Decide between a client and a test suite. Clients (Postman, Insomnia, Bruno, Hoppscotch) are for sending and debugging requests. Test tools (Katalon Studio, ReadyAPI, Karate, REST Assured) are for regression suites with assertions, data, and CI runs.
3. Match your team's skills. Keyword steps suit testers; code-first tools suit developers.
4. Price the whole team. Check per-user prices, CI add-ons, and which features sit on paid tiers.
5. Test the import path. Import one real SoapUI project or WSDL before you commit.

If you are comparing API clients more broadly, see our guide to Postman alternatives, and for a head-to-head of two tools on this list, Katalon vs Postman.

Verdict

Stay on SoapUI Open Source if its free features still cover your tests, or move to ReadyAPI if you want the same project model with data-driven tests, virtualization, and security scans and the budget allows it. Choose Postman for REST-first API exploration and sharing, Karate or REST Assured for API tests in code, and Insomnia, Bruno, or Hoppscotch for a lighter client.

Choose Katalon Studio if you have SOAP and REST services, want to import SoapUI projects and WSDLs instead of rebuilding them, and want API tests next to web, mobile, and (on a paid plan) desktop tests in one project. Try the 30-day free trial against one of your own SoapUI projects before you decide.