API security breaches are on the rise, and the OWASP API Top 10 has become essential reading for every developer. We tested and ranked the best API security testing tools — from enterprise-grade scanners to developer-friendly platforms — to help you catch vulnerabilities before they reach production.
APIs are the backbone of modern applications. They connect services, move data, and power everything from mobile apps to microservices. But every API endpoint is also a potential attack surface. The OWASP API Top 10 — a regularly updated list of the most critical API security risks — has become the de facto standard for understanding where APIs are most vulnerable.1
The good news? You don't have to wait for a penetration test in production to find these issues. Shifting security left — integrating security testing into your development workflow — catches flaws early, when they're cheapest and fastest to fix. Here are the best API security testing tools for developers, ranked.
Best for: Teams that need dedicated, automated security scanning for REST, SOAP, and GraphQL APIs.
ReadyAPI is SmartBear's enterprise-grade platform that combines functional, security, and load testing in one suite.1 Its security scanning module is purpose-built for APIs — it doesn't just check for generic OWASP Top 10 web vulnerabilities, but specifically tests for API-level threats like excessive data exposure, mass assignment, and broken object-level authorization.
What sets ReadyAPI apart is its ability to run security scans as part of a CI/CD pipeline without requiring a separate security team. You define your API contracts, and ReadyAPI generates security tests automatically. It supports REST, SOAP, and GraphQL, making it a strong fit for organizations with diverse API ecosystems.
Key strengths:
Best for: Individual developers and teams who want to add security checks into their existing API testing workflow.
Postman is the industry-standard API platform, used by millions of developers for designing, building, and testing APIs.2 While it's primarily known for functional testing, Postman's scripting capabilities (Pre-request and Post-response scripts) let you build security validation directly into your test collections.
You can write automated checks for authentication failures, input validation, rate limiting, and response data exposure. Combined with Postman's collection runner and Newman (its CLI tool), these security checks can run in CI/CD just like any other test.
Postman won't replace a dedicated security scanner for deep vulnerability analysis, but it's the most accessible way to start adding security testing to your daily workflow — especially if you're already using Postman for development.
Key strengths:
Best for: Teams working extensively with SOAP services or needing advanced functional testing before security scanning.
SoapUI is the open-source foundation that ReadyAPI is built on, and it remains a powerful tool for functional and regression testing of both SOAP and REST APIs.1 While SoapUI doesn't include dedicated security scanning out of the box (that's ReadyAPI's domain), it excels at the functional testing layer that security depends on.
You can build comprehensive test suites that validate authentication flows, data integrity, and error handling — all of which are critical for API security. For teams that need to test complex SOAP services alongside REST endpoints, SoapUI's support for WSDL and WS-Security standards is unmatched.
Key strengths:
Best for: Developers who want security vulnerability scanning integrated into their IDE and code review process.
Amazon Q Developer (formerly CodeWhisperer) is AWS's AI-powered coding assistant that includes security vulnerability scanning as a core feature.3 Unlike the other tools on this list, Amazon Q Developer works at the code level — it scans your code as you write it, flagging potential security issues like hardcoded credentials, injection vulnerabilities, and insecure API calls.
For API security specifically, Amazon Q Developer can catch issues in how you're implementing API calls, authenticating requests, and handling responses. It's not a replacement for runtime API security testing, but it's an excellent addition to a shift-left strategy — catching problems before they ever reach a test environment.
Key strengths:
| Tool | Testing Type | API Support | CI/CD Integration | Best For |
|---|---|---|---|---|
| ReadyAPI | Security + Functional + Load | REST, SOAP, GraphQL | ✅ Full pipeline integration | Enterprise security scanning |
| Postman | Functional + Scripted Security | REST, GraphQL | ✅ Newman CLI | Developer workflow security |
| SoapUI | Functional | REST, SOAP | ✅ Via CLI | SOAP & complex API testing |
| Amazon Q Developer | Code-level Vulnerability Scan | Any (code analysis) | ✅ IDE integration | Catching flaws during coding |
The traditional approach to API security — test in staging or production, fix after the fact — is expensive and risky. A vulnerability found in production can cost 10–100x more to fix than one caught during development.
Shifting security left means integrating security testing into the development phase: running security scans alongside unit tests, checking for vulnerabilities in CI/CD pipelines, and using IDE plugins that flag issues as you code. The tools above support this approach at different levels — from code analysis (Amazon Q Developer) to functional testing (Postman, SoapUI) to dedicated security scanning (ReadyAPI).
No single tool covers everything. The best approach is a layered one: use code-level scanning during development, add security checks to your functional tests, and run dedicated security scans before deployment.
Disclosure: As an Amazon Associate and affiliate partner for SmartBear products, AskBuy earns from qualifying purchases. This doesn't affect our recommendations — we only recommend tools we believe provide real value for developers.
This page was written by the engine and the engine is still on the line. The conversation below picks up where the article stops.
Yes — the picks above are the engine's current verdicts. Ask a sharper version of this question below and you'll get a custom answer with the latest pricing.