Application programming interfaces (APIs) serve as the glue connecting modern software applications. As APIs continue proliferating across the tech landscape, effective tools for API testing grow increasingly pertinent.
Two of the most widely adopted solutions include SoapUI and Postman. However, with overlapping capabilities, how do cybersecurity professionals determine which solution best fits their testing needs?
In this comprehensive guide, I unpack the differences between SoapUI and Postman to provide actionable recommendations on navigating this decision for your API testing requirements.
The Vital Importance of API Testing
First, let‘s briefly level-set on why API testing represents such a critical discipline.
APIs allow software to exchange data and functionality, serving as key integration points across architectures. API-related failures directly impact user experiences and business operations.
For example, payment APIs may connect e-commerce sites to payment gateways. Performance issues here cut off revenue streams.
As API usage proliferates – with 81% of organizations reporting API usage growth over 12 months according to Postman‘s 2022 State of the API Report – dedicating resources towards API testing becomes imperative.
API Standards: SOAP vs REST
While many specifications exist, APIs generally follow one of two dominant standards:
SOAP: Simple Object Access Protocol uses strict XML-based messaging with built-in security, transactions and other enterprise capabilities.
REST: Representational State Transfer adheres to looser design principles focused on scalability and web integration via HTTP requests.
Cybersecurity gurus should familiarize themselves with both standards to assess relevant tools like SoapUI and Postman.
Introducing SoapUI and Postman
Now that we‘ve established the immense value of bulletproof API testing, let‘s overview the two solutions in question:
SoapUI – Advanced Testing Focused on SOAP & Security
SoapUI provides an open-source functional testing tool focused mainly on rigorously vetting API logic and security.
Originated in 2004, SoapUI offered early support for SOAP API testing. And despite growing REST adoption, SOAP maintains decent market share creating ongoing need for SoapUI‘s area of expertise.
In addition to API testing, key features include:
- Load testing
- Security scanning
- Mock test environments
- Data-driven testing
- Continuous integration
SoapUI focuses on enabling technical testers to build automated testing pipelines.
Postman – Intuitive API Testing with Collaboration
Postman began life in 2012 as a Google Chrome plugin specifically for intuitive REST API testing.
The tool expanded to support additional API types while also integrating collaboration capabilities to position itself as an end-to-end API development platform, covering:
- Manual testing
- Automated scripts
- Mock servers
- Documentation
- Team workspaces
This combination of ease-of-use plus collaboration extracted Postman from humble beginnings as a REST helper to an API testing staple managing over 107 million APIs today.
Comparing Key Capabilities
While both qualify as capable solutions, SoapUI and Postman each have areas of specialization. Let‘s compare across vital testing criteria:
Debugging Support
Effective debugging plays an integral role identifying issues with API logic during testing.
SoapUI offers test case debugging to add breakpoints and analyze raw request/response payloads.
Postman enables similar functionality via its integrated console to inspect intermediary app behavior.
Verdict: Roughly equivalent debugging capabilities.
Test Automation
Executing automated API test cases is vital for scaling validation processes over time.
SoapUI utilizes built-in scripting for test automation allowing advanced logic.
Postman enables running sequential test scripts through its Collection Runner feature.
Verdict: SoapUI provides deeper test automation while Postman offers an easier path to get started.
Collaboration Tools
For distributed teams, collaborative testing tools proves mandatory for visibility and coordination.
SoapUI allows creating shared projects with basic permissions for team access.
Postman delivers more polished team experiences through its integrated Workspaces model managing rights across different groups.
Verdict: Postman dominates here by purposefully positioning itself as the better collab tool.
Additional Perspectives
Stepping back, a few other interesting differences emerge:
- Reporting: SoapUI generates more detailed test analysis reports
- Scripting: Postman standardized on JavaScript while SoapUI relies on Groovy and XML
- Integrations: Postman offers significantly more third-party platform integrations
- Design: Postman focused heavily on intuitive user experience
Alignment with API Standards
As discussed earlier, the origins of SoapUI and Postman trace back to different API standards – SOAP and REST respectively.
And while both expanded to cover additional standards, heritage matters when selecting the right tool:
- SoapUI still specializes around rigorous SOAP API test processes
- Postman provides a more streamlined experience for REST API testing
So consider your API type mix – legacy SOAP vs modern REST – as an input when deciding between the two.
Recommended Use Cases
Expanding beyond the technical comparison, what specific scenarios indicate one solution over the other?
SoapUI Use Cases
Consider SoapUI if:
- You maintain a large portfolio of SOAP-based interfaces
- Security vulnerability scanning is important
- Your team prefers open-source tooling options
- You want to load test APIs under heavy simulated traffic
- Customized test analysis reporting becomes vital
Generally SoapUI works best for advanced testing teams with SOAP and security tilted needs.
Postman Use Cases
Opt for Postman when:
- Your focus stays on REST API testing
- Quickly spinning up manual tests and basic scripts is key
- You want to on-ramp less technical team members
- Collaborating with distributed team members proves essential
- You appreciate beautifully designed user experiences
For testers that need breadth over depth, Postman is likely the better direction.
Best Practices for Bulletproof API Testing
Beyond just tools, proper process isking for maximizing test impact. Here are 12 cybersecurity guru tips for invincible API validation regardless of solutions selected:
Planning Stage
- Outline all test scenarios based on use cases
- Consult API documentation to form edge case hypotheses
- Define expected vs actual outputs per test
Manual Testing Stage
- Leverage both valid and invalid test input values
- Inspect raw request/response bodies at each step
- Document manual testing results in shareable format
Automated Testing Stage
- Script regression tests for previous defects
- Reuse sections of scripts between test cases
- Integrate with CI/CD pipelines to run on commits
Results Analysis Stage
- Configure alerts for new failures in testing
- Analyze performance testing trends over time
- Deliver automated reports to senior leadership
Maintenance Stage
- Tag failing tests with metadata for easier triage
- Continuously expand test cases to match new features
- Maintain strict version control and changes logs
Get these fundamentals engrained early to ensure peak testing hygiene regardless of tools.
Head-to-Head Recommendation
For readers still wavering between SoapUI vs Postman, I‘ll provide my straight-up recommendation based on your situation:
Lean Towards SoapUI If:
- Your APIs skew towards SOAP over REST
- You want advanced test automation capabilities
- Testing security vulnerabilities is important
- Customized reporting and hardcore data analysis is required
Lean Towards Postman If:
- Your API portfolio focuses on REST
- Quickly getting started with intuitive tests is key
- Enabling less technical team members is vital
- Tight collaboration within distributed groups is necessary
Use this guidance in conjunction with the detailed comparisons provided earlier to feel confident picking your corner in the SoapUI vs Postman decision.
Next Steps
Hopefully this guide served its purpose in detailing the SoapUI vs Postman debate and providing actionable direction for your API testing efforts.
As next steps:
- Take stock of your current API testing hygiene
- Document the priorities and use cases holding you back
- Research the free trials for both SoapUI and Postman
- Put the recommendations here into practice on your critical interfaces
Wishing you legendary API testing outcomes leveraging the perfect tools for your needs!
Let me know if any additional questions come up.
