Top 10 Open source / Free DAST Tools Compared
We relied on our research on vulnerability scanning tools and DAST to select leading open-source DAST tools and free versions of proprietary DAST software. See our rationale by following the links on product names:
As the cost and frequency of cyberattacks increase, businesses are increasingly adopting DAST tools to enhance their security posture.
Open source or free DAST software is the lowest cost entry point to DAST software and may be suitable for
- SMEs
- businesses starting their cybersecurity journey
- businesses that are looking for additional DAST tools to complement their cybersecurity posture
Free DAST tools
Sorting: According to number of stars on GitHub.
Sources: The OWASP organization maintains a list of DAST tools, many with free versions (check the “License” column).6
Inclusion criteria for:
- Open source projects: 900+ stars on GitHub
- Proprietary software: Must be a free-to-use package provided by a DAST software provider
ZAP
ZAP is the most widely used open-source DAST tool by GitHub stars. It covers automated vulnerability scanning, manual web app penetration testing, and REST API testing, making it the practical default for teams new to DAST.
ZAP functions as a transparent proxy, intercepting traffic between a browser and a web application for real-time analysis, and can also run in active scanning mode against predefined vulnerability rules. It is community-maintained under OWASP, actively developed, and has a broad ecosystem of add-ons and documentation.
ZAP added first-phase integration with the OWASP PenTest Kit (PTK), a browser extension that is now pre-installed in ZAP-launched browsers. This enables authenticated-session testing workflows, particularly relevant for single-page applications, by bridging browser-level session state directly into ZAP’s scanning pipeline.
Nikto
Nikto is an open-source web server scanner that tests for dangerous files and CGIs, outdated server software, misconfigurations, and other common issues. It is command-line only with no graphical interface.
Recent updates:
- Significantly faster scans
- New domain-specific language (DSL) for defining checks
- Report format changes; cookies enabled by default
- Randomized User-Agent to reduce fingerprinting
- Rewrote the LFI (local file inclusion) testing module
- License changed to GPLv37
Limitation: No GUI; operates entirely from the command line, which raises the barrier for non-technical users.
Arachni
Arachni’s GitHub repository now explicitly marks the project as obsolete. The last release date is 2022 (v1.6.1.3 era), and the project is no longer actively maintained. Its modular design and advanced crawling capabilities were notable during its active years, but teams should treat it as end-of-life and evaluate ZAP or Wapiti as replacements.
OpenVAS
OpenVAS is an open-source vulnerability scanner designed to detect security issues across computer systems and networks, forming the core of the Greenbone Vulnerability Management (GVM) framework. It scans for known CVEs, misconfigurations, and outdated software across both small and enterprise-scale environments.
Classification note: OpenVAS is primarily a network and host vulnerability scanner, not a web application DAST tool in the traditional sense. It belongs in this list as a frequently used adjacent tool, but it does not replace ZAP or Wapiti for web-app-specific dynamic testing (form injection, session handling, client-side logic). Use it for host/network coverage; use ZAP or Wapiti for web application surface coverage.
Wapiti
Wapiti is a black-box web vulnerability scanner. It works by crawling a deployed web application, extracting links, forms, and scripts, and then injecting payloads into discovered parameters to detect abnormal application behavior that indicates vulnerabilities. It also supports a passive mode for traffic analysis without active fuzzing.
Wapiti supports custom scripting to extend its vulnerability detection capabilities, making it useful in specialized environments where the default rule set needs augmentation.
Proprietary tools that are free for open source projects
CI Fuzz (Code Intelligence)
A command-line fuzz testing tool focused on embedded applications, primarily in automotive and medical device contexts. Free for open-source projects.
StackHawk (HawkScan)
StackHawk is the most established free API security testing tool in this list and one of the few commercial DAST products with dedicated API testing as its primary focus. Open-source project maintainers can use it at no cost.
StackHawk’s current platform positioning has expanded beyond API-only testing to include attack surface discovery from source code, runtime testing, and Modern AJAX Spider capabilities (SPA framework-aware crawling). The free-for-OSS tier remains available while the commercial platform grows around it.
Recent releases:
- v5.3.0 (February 17, 2026): Added JSON-RPC scanning; rewrote the Modern AJAX Spider for SPA framework awareness; added DOM XSS sink detection; migrated to Chrome/Puppeteer for browser automation; faster initialization
- v5.2.0 (January 15, 2026): Improved alert triage workflow; reduced SQLi false positive rate8
Proprietary tools with free community editions
For more on these tools, see Tenable Nessus alternatives or a full list of DAST tools.
Other free application security tools
DAST is one component of a broader application security program. Open-source and free SAST tools provide complementary static analysis, catching issues at the code level that DAST cannot see at runtime. A mature security posture combines both.
In 2026, the market is moving toward correlating DAST and SAST findings, surfacing a runtime vulnerability and tracing it back to the specific code location simultaneously. Snyk’s “AI Security Fabric” is one example of this direction becoming a product feature rather than a manual process.9
Benefits of open-source DAST tools
They provide a fast and cost-effective way to address the present threat from external actors by offering testing capabilities accessible to organizations of all sizes and budgets:
- Lower upfront cost: No licensing negotiation or procurement process. Download, configure, and scan.
- Fast deployment: For teams without an established security testing pipeline, a tool like ZAP or Nikto can be running against a staging environment within hours of a decision to test.
- Simpler configuration for standard use cases: Several tools in this list work well out of the box for common web application patterns without requiring deep tuning.
- Active communities: The most established tools (ZAP in particular) have large user communities, public documentation, and maintained add-on ecosystems. Community forums substitute for the vendor support that comes with paid tools.
- No vendor lock-in: Results belong to you. Integration with CI/CD pipelines is flexible since the tools are open and scriptable.
Recommendations for choosing an open-source DAST tool
You can easily try out these solutions in test runs on your company’s applications and compare alternatives. It is important to measure these for different solutions:
- % of correctly identified vulnerabilities
- % of false positives in all identified vulnerabilities
- Remediation guidance: How useful is the tool in describing how to resolve issues?
- CI/CD integration: Can it run headlessly in a pipeline without manual intervention?
- Scan speed: If it gates deployments, a 45-minute scan on a large application is a workflow problem
- Resource usage: Deep active scans are computationally intensive; ensure test infrastructure is sized appropriately
- Customization: Does the tool support extensions or custom rules for your application’s specific technology stack?
Why Invest in DAST at All?
DAST catches a class of vulnerabilities that static analysis and code review routinely miss, specifically, issues that only manifest when the application is running and processing real requests. Authentication weaknesses, session management flaws, and misconfigurations in deployed infrastructure are the most common examples.
The three primary attack vectors organizations face are compromised credentials, phishing, and vulnerability exploitation. Unencrypted data in transit sits at the intersection of all three. DAST directly tests:
- Whether sensitive data is exposed in transit
- Whether session tokens can be hijacked or forged
- Whether authentication controls (password policies, account lockout, authorization checks) hold up against active manipulation
The consequences of failures in these areas, such as financial theft, PII exposure, and operational disruption, are well-documented and escalating in cost year over year.
More on DAST & AppSec testing
- Top 10 Application Security Tools
- Top 10 Free PAM Solutions
- DAST Use Cases, Examples, Pros & Cons
- IAST Tools
Reference Links
Cem's work has been cited by leading global publications including Business Insider, Forbes, Washington Post, global firms like Deloitte, HPE and NGOs like World Economic Forum and supranational organizations like European Commission. You can see more reputable companies and resources that referenced AIMultiple.
Throughout his career, Cem served as a tech consultant, tech buyer and tech entrepreneur. He advised enterprises on their technology decisions at McKinsey & Company and Altman Solon for more than a decade. He also published a McKinsey report on digitalization.
He led technology strategy and procurement of a telco while reporting to the CEO. He has also led commercial growth of deep tech company Hypatos that reached a 7 digit annual recurring revenue and a 9 digit valuation from 0 within 2 years. Cem's work in Hypatos was covered by leading technology publications like TechCrunch and Business Insider.
Cem regularly speaks at international technology conferences. He graduated from Bogazici University as a computer engineer and holds an MBA from Columbia Business School.
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