Top 10 API Security Testing Tools for Mobile Apps in 2025

According to Salt Security's 2024 State of API Security Report, 80% of API attacks attempt to exploit one or more OWASP API Security Top 10 vulnerabilities. Yet, only 58% of organizations prioritize protection against these well-known threats. This gap leaves many businesses exposed to cyber risks that could have been prevented.

Investing in API testing tools helps safeguard your mobile application ecosystem against evolving threats. The best security testing tools scan all APIs in your ecosystem, whether public or internal and ensure that third-party APIs and microservices are thoroughly tested for vulnerabilities.

Let’s look at a few reasons why you should invest in an API security testing tool for your organization. We’ll also explore the top API security testing tools in the market with their pros, cons, and pricing. 

Why is API security testing critical for mobile apps?

Mobile apps are the heartbeat of modern digital experiences, but are only as secure as the APIs that power them. One weak link in your API security can expose your entire application—and your users—to devastating cyber risks.

1. Data protection and privacy

APIs handle your users’ sensitive data, including personal, financial, login credentials, and health records. Poor API security can lead to unauthorized access, exposing confidential information to cybercriminals.

2. Preventing account takeover

Weak authentication and authorization mechanisms can allow attackers to hijack accounts, leading to identity theft, fraud, and data manipulation.

3. Business continuity and service availability

APIs are targets for Denial-of-Service (DoS) attacks, which can slow down or crash services and affect user experience and business operations. Implementing rate limiting and access controls helps mitigate these API risks.

4. Reputation and compliance risks

A security breach can damage a company's reputation and erode customer trust. Additionally, enterprises must ensure compliance with regulations like GDPR, HIPAA, PCI-DSS, and ISO 27001, making API security essential to avoid legal and financial penalties.

5. Expanding attack surface

The rise of microservices and third-party integrations increases the number of API endpoints, making them attractive targets for attackers. Ensuring secure coding practices, API monitoring, and regular API security testing is critical to reducing API vulnerabilities.

6. Unique API vulnerabilities 

APIs introduce unique security challenges that traditional web protections may not address. Shadow and zombie APIs that are untracked or outdated endpoints create hidden vulnerabilities. 

Additionally, poor input validation can allow injection attacks like SQL or XML External Entity (XXE) exploitation. Addressing these risks requires specialized mobile API security measures beyond standard web security practices.

What to look for in an API security testing tool?

1. Accuracy

A strong API security tool must minimize false positives and provide precise vulnerability detection. This will ensure that your security team focuses on real threats instead of spending time filtering through unnecessary alerts. 

Pro tip: Choose top API testing tools, like Appknox, that offer <1% false positives and negatives, the lowest in the industry. 

2. Comprehensive coverage

Your API security tool should provide broad protection against threats, including misconfigurations, business logic vulnerabilities, and real-world attack simulations. 

Pro tip: The top API security testing tools online must combine manual security testing with automated scans to perform deeper API security assessments. 

3. Scalability

Your API security tool must scale with your business as it grows. A reliable solution should be capable of handling large API ecosystems, supporting multiple endpoints, versions, and applications without compromising performance or efficiency.

4. Automated vulnerability detection

A security tool should automatically detect critical API risks, such as broken authentication, excessive data exposure, and injection attacks. Automation eliminates manual effort and ensures vulnerabilities are identified and fixed before they can be exploited.

Pro Tip: Appknox uses automated DAST to simulate real-world attacks, uncover hidden vulnerabilities, and strengthen your API security with minimal effort.

5. Integration with CI/CD pipelines for DevSecOps

The API security testing tool you choose should seamlessly integrate into CI/CD pipelines, allowing for continuous security checks before production. A good tool should support platforms like GitLab CI/CD and Azure DevOps to enable automated security scanning within development workflows.

6. Compliance and regulatory support

APIs handling sensitive data must comply with GDPR, HIPAA, and PCI-DSS. The right security tool should detect compliance gaps, help enforce security controls, and generate audit-ready reports to ensure adherence to industry regulations.

7. Detailed reporting and real-time alerts

The right API security tool should provide comprehensive reports with CVSS scores, remediation steps, and real-time alerts. This helps teams react quickly to vulnerabilities and make informed security decisions.

Top 10 API security testing tools in 2025 

1. Appknox

With a mobile-first approach, Appknox is one of the best API security testing tools that leverages a combination of automated and manual testing to identify vulnerabilities such as broken authentication, injection attacks, and misconfigurations.

The platform performs automated API discovery to ensure all mobile-connected APIs are detected and integrates Dynamic Application Security Testing (DAST) for real-time analysis. 

With <1% false positive rates, Appknox ensures highly accurate results, reducing unnecessary noise for your security teams. Additionally, Appknox helps you maintain compliance with industry standards such as PCI-DSS, GDPR, and ISO 27001, making it easier to meet regulatory requirements while keeping your APIs secure.

Key features

Automated API discovery  
Appknox scans mobile applications to identify all API endpoints, including shadow APIs (undocumented APIs that may expose security risks). This reduces blind spots and helps you secure every API your app interacts with.

Dynamic API Security Testing (DAST) 
Appknox integrates API security testing with DAST to take a unified approach to detecting vulnerabilities. This uses real-time testing to analyze API vulnerabilities by simulating real-world attack scenarios without requiring access to the source code.

Manual penetration testing 
Appknox’s security experts conduct manual tests to uncover business logic flaws, insecure authentication mechanisms, and authorization bypasses that automated scanners might miss.

Customizing API scans 
Appknox allows you to customize API security scans to fit your testing needs. You can define scan parameters, such as targeting specific API endpoints, authentication mechanisms, or data payloads to focus on critical areas. 

You can also adjust the depth of the testing, choosing between quick scans for common vulnerabilities and deep scans for advanced threats.

Pros 

• DAST scans are done on real devices, not emulators 
• Less than 1% false positive rates 
• Identify vulnerabilities in <60 seconds  
• Provides detailed reports that break down vulnerabilities with risk levels to help you prioritize remediation efforts

Pricing 

• Flexible, usage-based pricing 

Rating
Gartner: 4.8/5

2. Burp Suite

Burp Suite is an API security testing tool designed both for manual and automated vulnerability assessments. It allows you to intercept, modify, and replay API requests using Burp Proxy and Repeater, which helps identify authentication flaws, injection attacks, and access control issues. 

The Burp Scanner automates the detection of API-specific vulnerabilities, such as CORS misconfigurations, exposed API keys, and improper authorization mechanisms. In contrast, the Burp Intruder facilitates automated attacks to test rate limiting and parameter tampering. 

Pros 

• Burp Extender allows you to develop and integrate custom security plugins, enabling advanced API security assessments.
• Web-first application security testing tool 

Cons 

• Since it’s a web-first application security testing tool, it may not be ideal for mobile-first apps.  
• Burp Suite does not natively integrate with CI/CD pipelines, making continuous API security testing harder to automate in development workflows.

Pricing 

• Custom pricing 

Rating 

• Gartner: 4.7/5 

3. NowSecure 

Utilizing an advanced dynamic test engine, NowSecure discovers all mobile-connected APIs, flags potential violations against the OWASP API Top 10 standards, and identifies unapproved "shadow APIs" that could pose security risks. 

Designed for complex mobile app configurations, NowSecure utilizes the NowSecure Workstation, a pre-configured system that performs API security tests using open-source tools like Frida and Radare. 

Pros

• The platform provides fully automated security testing aligned with the OWASP API Security Top 10, reducing the need for manual assessments.
• Use of actual devices instead of emulators for scans 

Cons 

• Lacks manual penetration testing for APIs, which is necessary for deeper security validation 

Pricing 

• Custom pricing 

Rating 

• Gartner: 4.6/5 

4. Postman

Postman provides default security rules based on the OWASP API Security Top 10, automatically identifying common vulnerabilities in API definitions and requests. 

Moreover, you can write test scripts and run automated authorization tests and mocking to prevent regressions. The platform also automatically scans public API collections and documentation for sensitive tokens (e.g., API keys, private keys) and notifies users of potential leaks.

Pros 

• Allows you to define security policies using Spectral-based custom rules, offering flexibility in API governance

Cons 

• Postman focuses on pre-deployment security but does not offer in-depth runtime security analysis. 

Pricing 

• Free:$0
• Basic: $19/user per month 
• Professional: $39/user per month 
• Enterprise: Custom pricing 

Rating 

• Gartner: 4.6/5 

5. OWASP ZAP

OWASP ZAP (Zed Attack Proxy) API scan is designed to perform security testing on APIs defined by OpenAPI, SOAP, or GraphQL. 

You can run the scan via a command-line interface with multiple reporting formats (HTML, Markdown, XML, JSON) and fine-tune the process with various options, such as adding custom rules, attack strength, alert thresholds, or running authenticated scans.

Pros 

• Open-source, free tool 
• Runs in a Docker container, making it easy to deploy and run API security scans without installing ZAP manually 

Cons 

• No updates or improvements since it's a free tool 
• Offers only automated scans, no manual security testing to detect nuanced vulnerabilities 

Pricing 

• Free 

Rating 

• Gartner: N/A 

6. Checkmarx

Checkmarx’s automated API discovery scans code repositories to identify all the API endpoints and offers complete visibility into the API landscape. 

The platform detects new or updated APIs during code check-ins or compilations, ensuring continuous tracking throughout the development lifecycle. By comparing the complete API inventory against existing documentation, Checkmarx detects shadow and zombie APIs to reduce hidden security risks. 

Pros 

• Uses risk-based analysis to highlight critical vulnerabilities to help you focus on serious issues first
• Provides deep visibility into APIs by analyzing source code, enhancing security at a foundational level 

Cons 

• Focuses primarily on static analysis and code-level discovery, making it less effective for runtime API behavior analysis
• Since it relies on static analysis, it might flag issues that aren’t actual security threats in a real-world environment.

Pricing 

• Custom pricing 

Rating 

• Gartner: 4.6/5 

7. ImmuniWeb

ImmuniWeb offers API penetration testing, security scanning, and continuous monitoring capabilities to help you mitigate risks and maintain a strong security posture. 

Leveraging machine learning algorithms to conduct security testing, ImmuniWeb provides zero false positives and allows you to upload API definitions in various formats such as Postman, Swagger, and GraphQL. 

Pros 

• Provides a Service Level Agreement that guarantees zero false positives 

Cons 

• The absence of automated tagging requires manual intervention, potentially affecting workflow efficiency.

Pricing 

• Custom pricing 

Rating 

• Gartner: 4.9/5 

8. API Fortress

API Fortress is a continuous testing platform that offers automated functional, performance, and security testing for internal, partner, and third-party APIs. 

Additionally, its unified monitoring capabilities allow real-time oversight of API performance, helping you to detect and address potential issues before they escalate.

Pros 

• Offers features for documenting APIs, thereby streamlining the process of maintaining and updating API documentation 

Cons 

• Some users have reported performance issues when handling very large datasets or intricate test scenarios, affecting testing efficiency.

Pricing 

• Custom pricing 

Rating 

• Gartner: N/A 

9. DataTheorem

DataTheorem takes a multi-faceted approach, including SAST, DAST, SCA, and customized testing to identify vulnerabilities in your APIs. 

Utilizing black box discovery methods without needing agents or configurations, DataTheorem continuously monitors APIs across multi-cloud environments, including AWS, Azure, GCP, and private clouds. 

Pros 

• Takes proactive measures such as encryption, bot protection, and attack prevention to protect APIs 

Cons 

• Implementing and fully utilizing DataTheorem's features may require a learning period.

Pricing 

• Custom pricing 

Rating 

• Gartner: 4.6/5 

10. Astra Pentest

Astra Pentest performs a combination of SAST, DAST, and continuous API discovery to ensure a thorough evaluation of your API security. The platform tests your APIs against over 10000+ known vulnerabilities, including the OWASP API Top 10 to detect vulnerabilities. 

With an intuitive dashboard for seamless collaboration between teams and certified security experts, you can track vulnerabilities in real time and prioritize fixes based on potential impact.

Pros 

• Combines automated scans with manual testing by security experts to uncover complex vulnerabilities

Cons 

• Lacks customization options in scan settings, limiting the ability to tailor API tests to specific needs 

Pricing 

• Custom pricing 

Rating 

• Gartner: 4.5/5

TL; DR: Choosing the best API security testing tool 

To get started with API security testing, you can use open-source/free tools available in the market to detect vulnerabilities early in the development cycle. 

However, if you’re an enterprise organization managing an app portfolio of hundreds of live mobile apps, you’ll need a more robust API security testing tool like Appknox for proactive threat detection and response. 

The key highlights of Appknox as one of the best API security testing tools are: 

• Automate API discovery within your mobile applications 
• Simplify workflows and take a cohesive approach with DAST integrations 
• Run API security scans on selected APIs that align with your testing objectives 
• <1% false positives and negatives 
• Real-time updates on a unified dashboard 
• Detailed reports in <60 minutes
   

Sign up for a free trial and strengthen your API security with Appknox.