Best API Security Testing Tools

If you searched for “best API security testing tools,” you want to evaluate and choose. This guide focuses on selection, not theory. We cover DAST against APIs, spec linting and shift left controls, and platforms that combine discovery, posture, and runtime with test automation. We also show where traditional “API testing” tools fit, since many now add security checks.

APIs run modern products, which makes them an attractive target. Teams often ask the same question, which API security testing tools actually reduce risk without slowing engineers. In this guide you will get a practical, current comparison of the best platforms and scanners, how they fit into the lifecycle, and a clear selection framework you can use today. We map capabilities to common threats from the OWASP API Top 10, show where each tool shines, and share proven workflows for design time checks, CI testing, and pre-prod or prod discovery. You will also see credible data points and references to help you justify your choice with leadership. Our goal is simple, help you pick and deploy the best API security testing tools for your stack and ship safer services

What counts as “API security testing” in 2025

API security testing verifies that API designs, implementations, and deployed endpoints resist common attacks, cover the OWASP API Top 10, and follow governance rules across design, CI, and runtime. It includes contract linting, active testing in CI, and discovery plus posture checks in staging or production

Why this matters now

• APIs are a top target for attackers according to Postman’s latest State of the API research. Security and compliance rank among the biggest integration pain points. Postman
  
• NIST published SP 800-228, guidelines for API protection in cloud native systems, which stresses governance, least privilege, and end-to-end visibility. Testing must cover the full lifecycle. NIST Publications
  
• The market evolved from scanners only to full lifecycle platforms that combine discovery, posture management, and testing. Analysts label this segment API protection. Gartner

The selection framework

Use these criteria to compare tools:

1. Coverage by phase, design time, CI pipeline, pre-prod, and production discovery.
2. Spec awareness and governance, OpenAPI validation, custom lint rules, and contract tests.
3. Attack realism in CI, ability to test REST, GraphQL, gRPC, and SOAP.
4. Auth support and environment handling, tokens, OAuth flows, API keys, mTLS.
5. Runtime feedback loop, findings from production drive tests in CI.
6. Developer experience, config as code, cURL reproduction, Git and ticketing integrations.
7. Proof of control for OWASP API Top 10, BOLA, broken auth, excessive data exposure, and more.

Choose by API style, auth, and risk

Start with the shape of your APIs, then map risks and required depth.

• API styles. REST with OpenAPI, GraphQL with persisted queries, gRPC, or event driven.
  • Design driven stacks with OpenAPI. Favor spec linting and contract based testing, then add CI friendly API DAST.
  • GraphQL heavy stacks. Require depth in field level authorization checks, batching, aliasing, and introspection handling. Verify the tool supports GraphQL specific test cases, not only REST.
• Auth and sessions. OAuth, OIDC, mTLS, API keys, signed cookies, device tokens.
  • Pick tools that can model multi step auth, token refresh, and role switching. Ask how they record and replay flows in CI.
• Data sensitivity and exposure. PII, PHI, payments, or partner data raise the bar.
  • Combine pre prod testing with runtime discovery and anomaly detection. Testing alone is not enough for high exposure APIs.
• Change velocity. Fast moving services need automation.
  • Favor tools that can auto generate tests from specs or from your functional suites, then run on each commit.

Quick rule: design checks early, DAST in CI, runtime protection in production. Use all three for public, sensitive, or partner facing APIs.

Choose by team workflow and integration points

Select tools that fit how your teams ship code. If a tool does not run where developers live, it will be bypassed.

• Source control and CI. GitHub Actions, GitLab, CircleCI, Jenkins.
  • Require native CI jobs, clear exit codes, artifacts, and PR comments with developer friendly remediation.
  • Use fail on critical rules for specs and scanners, warn on medium issues until noise is under control.
• Service auth and secrets. Use your existing secrets manager.
  • Token rotation, environment scoping, and safe playback of auth in pipelines are must haves.
• Test data and fixtures.
  • Prefer tools that seed or reuse fixtures. Synthetic data should mimic real data shapes and boundary conditions.
• Observability and backlog.
  • Findings must flow into Jira or your issue tracker with owners, tags, and SLAs.
  • Metrics to watch, findings per service per week, false positive rate, fix time, and reintroduction rate.
• Security ownership model.
  • Developer led, emphasize guardrails and quick feedback.
  • Security engineer led, add proxy based exploration for business logic abuse.
  • Platform led, add discovery and posture so you always know what is exposed.

Litmus test: if a new joiner can run the checks locally and see the same results as CI, the integration is healthy.

Prove fit with a 10 day scorecard

Run a short, realistic trial against one high risk service. Score what matters to you, not what the brochure highlights.

Day 1 to 2. Setup and auth

• Time to first meaningful scan in CI.
• Effort to model auth and stateful flows.
• Ability to reuse your existing functional tests or specs.

Day 3 to 6. Signal quality

• True positives found on known vulnerable paths.
• Noise level. Count false positives and how you suppressed them.
• GraphQL or gRPC depth if relevant. Verify field level checks and schema awareness.

Day 7 to 8. Developer experience

• Clarity of remediation steps in PR comments.
• Performance impact on CI minutes.
• Local developer workflow parity.

Day 9 to 10. Ops and scale

• Multi service rollout steps.
• Role based access, project scoping, and reporting.
• Export of findings to your tracker and dashboards.

Scorecard template

• Coverage, 0 to 5
• Signal quality, 0 to 5
• Integration effort, 0 to 5
• Developer adoption, 0 to 5
• Total cost of ownership, 0 to 5

Pick the tool that wins on coverage and signal quality without breaking your CI budget, then keep one runner up as a specialty tool for complex cases like GraphQL or mobile backed auth.

Top API security testing tools, strengths and ideal use cases

The list below focuses on testing value. Some platforms also include discovery and runtime protection.

1) DeepStrike, expert led API security testing

What it is, human driven API penetration testing and advisory aligned to OWASP API Top 10, with developer ready proofs and fix guidance.

Where it shines

• Finds chained flaws and business logic issues scanners miss.
• Validates authorization models.
• Produces actionable tickets.

Best for organizations that want a focused, expert assessment, or to validate platform findings before production.

2) 42Crunch

What it is, Developer-first platform for OpenAPI contract security, CI scanning, and policy enforcement, with options that extend to runtime. 42Crunch

Where it shines

• Strong OpenAPI contract audit and guided hardening in IDE and CI.
• Design time to runtime policy continuity, useful for regulated teams. 42Crunch

Best for teams with many OpenAPI specs that want strict governance and predictable pipelines.

3) StackHawk

What it is, CI-centric DAST focused on applications and APIs, supports REST, GraphQL, gRPC, and SOAP. StackHawk, Inc.

Where it shines

• Fast, developer friendly scans in pull requests.
• Config as code, cURL reproduction, clean CI integrations. StackHawk, Inc.

Best for engineering teams that want automated, repeatable API security tests on every build. StackHawk, Inc.

4) Burp Suite API Scanner

What it is, Burp’s scanner can import OpenAPI and Postman collections to audit endpoints, with fine control over auth and parameters. PortSwigger+1

Where it shines

• Deep manual plus automated testing, great for security engineers.
• Mature ecosystem and extensions for API workflows. PortSwigger

Best for red teams and AppSec who want power user control and hybrid manual plus automated testing.

5) Akamai App and API Security, plus managed WAAP

What it is, App and API security with discovery, analysis, and a managed WAAP option that many teams pair with testing in CI. Recent partnerships highlight demand for packaged operations. Akamai+1

Where it shines

• Discovery of unmanaged APIs at the edge, managed response at scale.

Best for orgs that want WAAP plus API visibility and need vendor staffed operations.

6) Cequence Security

What it is, unified API discovery, risk testing, and protection with advanced bot and fraud defenses.

Where it shines

• Useful when API security and automated attack traffic intersect.
• Strong fit for commerce and fintech abuse cases.

Best for teams that need testing plus layered traffic defense in one platform.

7) Schemathesis

What it is, property based testing for OpenAPI and GraphQL that auto generates edge case requests.

Where it shines

• Catches boundary and logic bugs early.
• Integrates neatly with CI.

Best for engineering teams that want deeper negative tests from the contract itself.

8) FireTail

What it is, API security testing and posture management with code to cloud focus and quick start options.

Where it shines

• Bridges scanning with policy enforcement across environments.
• Helpful for smaller teams.

Best for teams seeking a fast path from scan to enforceable controls.

Conclusion

The best API security testing tool is the one your team will run daily, in the pipeline you already trust, with signal that drives fixes. Start with spec linting and CI friendly API DAST. Add discovery and runtime analytics for complete coverage. Validate with a short proof of value on your most complex API, then scale.