Top 9 Free Web App Vulnerability Scanners [Updated List 2025]

Quick Summary: Are you looking for a budget-friendly or free web application scanner to uncover vulnerabilities and boost cybersecurity? Check out the list of the best free web application security scanners in this blog, which was reviewed by experts, to make a choice. These scanners are well-suited for all types of organizations regardless of size and industry.

Web application security assessment is something you cannot ignore in today’s time. Your organization will pay a heavy price in terms of reputational damage, regulatory actions, and financial loss in case of a data breach. Exploitation of vulnerabilities is the primary reason behind data breaches, as shown in Verizon’s DBIR report.

However, security assessment can be challenging if you have a tight budget. Luckily, free web application scanners solve this problem. These vulnerability scanners or tools help evaluate web apps for security weaknesses without costly investment.

Using these free vulnerability scanners for web apps helps your organization uncover hidden vulnerabilities and take appropriate actions to remediate them before a hacker exploits them. Hence, you can keep your applications safe by eliminating all hidden security loopholes.

But the question is – how will you know which web application security scanner is best for you? This is a question we're going to give an answer to in this blog. Picking the right web app scanner is essential to perform quality scanning and discover vulnerabilities precisely.

We have curated a list of the top free web application vulnerability scanners in 2025 and evaluated them based on their accuracy, coverage, ease of use, and more. So, let’s explore these tools without further ado!

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What is a Web App Vulnerability Scanner?

Web app vulnerability scanners are security testing tools that check websites and web apps for common vulnerabilities and weaknesses. Such tools crawl different pages and components of a web app or website to inspect elements like forms, input fields, URLs, and more.

These tools can be used manually or automated to uncover hidden vulnerabilities that may allow an attacker to change your application’s behavior, steal sensitive data, or manipulate information. These scanners use a database of vulnerabilities to probe an app.

Free web application vulnerability scanners are variants of such tools that are available free of cost. These free scanners can be open-source or closed-source. They are ideal for continuous security testing. Usually, these scanners rely on publicly available databases of vulnerabilities such as OWASP, CWE, National Vulnerability Database, etc.

Best Free Web Application Vulnerability Scanners

The following vulnerability scanners are top tools to scan and discover vulnerabilities across a wide range of web apps. They offer great accuracy, speed, and features for security assessment.

1. ZeroThreat

ZeroThreat unifies automated vulnerability scanning with next-gen DAST capabilities to help you conduct comprehensive security audits. It offers a centralized platform to perform web application and API scanning to thoroughly analyze your attack surface from a single interface.

It scans your application even if it heavily uses JavaScript, regardless of its size. With a strong database, it scans web apps for 40,000+ vulnerabilities, including OWASP top 10 and CWE top 25, providing results with zero false positives. It allows authenticated scanning to test pages protected behind logins.

Key Features:

• Both credentialed and non-credentialed scanning
• Fuzz testing
• Scheduling vulnerability scans at specified intervals
• Detailed reports and vulnerability prioritization based on severity and business impact
• Out-of-band vulnerability scanning
• Scalable scanning
• Asset discovery
• AI-powered remediation reports
• Compliance-based scanning
• Reduce pentest efforts by 90%

2. ZAP

ZAP, which is an acronym for Zed Attack Proxy, is a free and open-source web app vulnerability scanner. It offers excellent features, including an alert mechanism, authentication and authorization, anti-CSRF tokens, and more.

ZAP can effectively detect common web application security vulnerabilities such as cryptographic failure, input validation issues, misconfigurations, and more. Key features like automated scanning, proxy, spidering, and passive scanning provide a comprehensive security assessment.

Key Features:

• Intercepting proxy to modify request/response
• Customize scanning with scan policy control
• Both active and passive scanning supported
• Authenticated vulnerability scanning
• ZAP supports fuzzing
• Ajax spidering

3. W3af

Another popular free web application security scanner on the list is w3af, which primarily focuses on the most critical vulnerabilities defined by OWASP. Although it offers a clean GUI-based interface for vulnerability assessment, there is also a console-based interface known as w3afconsole.

It dynamically tests applications and uses the black box testing method to discover and report vulnerabilities. It also uses plugins and scans web applications for more than 200 security threats, including SQL injection, cross-site scripting, remote file inclusion, and more.

Key Features:

• Both command-line (CLI) and GUI interfaces are available
• Fuzzing features test applications by sending unexpected inputs
• Detailed vulnerability scan reports
• Plugins help extend the functionality of this tool
• It can automatically discover URLs, directories, and vulnerable areas

4. OpenVAS

OpenVAS is an open-source and simple tool for web app vulnerability scanning. It offers both GUI and CLI-based vulnerability scanning capabilities. The tool offers an extensive database of vulnerabilities, enabling you to test your web application for a wide range of vulnerabilities.

You can tailor the scan configuration based on your requirement to perform more fine-grained vulnerability scanning. It allows you to pick the desired depth and breadth of scanning to perform security testing as per your business requirements.

Key Features:

• Task scheduling
• Authenticated vulnerability scanning
• Scalable scanning
• Detailed test reports
• Plugins to extend the tool's capabilities

5. Wapiti

As an open-source and free web app security scanner, Wapiti makes vulnerability testing quick and cost-effective. Besides, it discovers a wide array of vulnerabilities by allowing you to conduct scans for hundreds of security weaknesses.

It can discover the most common web application vulnerabilities, such as cross-site scripting, SQL injection, command injection, and more. Wapiti thoroughly scans your web apps, their components, and third-party integrations to uncover vulnerabilities and loopholes.

Key Features:

• HTTP, HTTPS, and SOCKS5 proxies
• Customize the scope of the scan
• Options to control the crawler limit and behavior
• Man-in-the-Middle proxy
• Test reports in multiple formats like XML, CSV, HTML, and JSON.
• Open redirects
• Detect uncommon HTTP methods

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6. Burp Suite Community Edition

Burp Suite Community Edition is a free and comprehensive web app security testing toolkit with multiple features and benefits. It is one of the best free web application vulnerability scanners you can use without paying a single penny.

Whether you prefer automated or manual testing, Burp Suite has got you covered. It offers the right features to support your testing preferences with customizable scanning and configurations. Built-in penetration testing tools for web applications help discover more complex vulnerabilities.

Key Features:

• Automated and manual scanning in one
• Payload options
• Fuzzing and brute-forcing
• HTTP/HTTPS proxies
• Entropy checker
• Built-in extender, decoder, and repeater

7. Wfuzz

Wfuzz is another open-source and free vulnerability discovery tool that identifies a wide range of security threats. It is widely known as a web fuzzer that sends input to a web application to check its response and detect any security weakness. It automatically scans your web application for common vulnerabilities such as open redirects and IDOR.

This tool offers many advanced features, filters, and customizations, allowing you to configure scans to your preferences. Wfuzz offers a wide range of fuzzing features like proxy, fuzzing paths and files, fuzzing custom headers, fuzzing cookies, and fuzzing POST requests.

Key Features:

• Wordlist-based fuzzing
• Assessment by HTTP request/response method
• Automated vulnerability scanning and detection
• Plugins to extend the functionality of Wfuzz
• Various fuzzing techniques to discover weaknesses

8. Arachni

It’s an open-source and free web app security testing tool built on the Ruby framework. It performs behavioral scans by monitoring application behaviors. Arachni also performs meta-analysis using different factors to accurately detect vulnerabilities and reduce false positives.

It can also inspect client-side code and scan complex applications built with heavy use of JavaScript, DOM manipulation, HTML5, and AJAX. Arachni performs platform fingerprinting and tailors scans according to underlying server-side technologies using applicable payloads.

Key Features:

• Use agent spoofing
• Proxy authentication
• Cookie-string/cookie-jar support
• Custom header support
• Adjust timeout for requests
• Support various proxy like SOCKS5, SOCKS4, HTTP/1.1, etc
• Detailed scan reports

9. Nuclei

Nuclei is also a free and open-source web application vulnerability scanner. It offers real-time vulnerability scanning and detection, helping you uncover security risks before attackers exploit them. With a database of over 9,000 common vulnerabilities and exposures like SQL injection, IDOR, and broken authentication, it is capable of detecting a wide range of known and complex security risks.

Key Features:

• Easy integration with ticketing and alerting systems
• Lower false positives
• Customizable scanning
• Authenticated scanning
• It depends on customizable detection templates (used in YAML format)
• Options for configuring and optimizing scans

What to Look for in a Free Web App Vulnerability Scanner?

While free web app security testing tools save you time and reduce overall costs in cybersecurity practices, choosing the right tool is vital to maximizing ROI. But how to choose the right vulnerability scanner with so many options out there? No worries! Consider the pointers given below to make the right choice.

Accuracy and False Positives

Even if a single vulnerability is flagged that doesn’t actually exist, you will end up wasting significant time and resources. So, the accuracy of your free web app scanner matters a lot. You must carefully evaluate different scanners to check different rates of false positives.

There are a lot of variations in false positives across scanners. For example, some may generate as little as 1-2% of false positives, and for some scanners, this rate may be around 20-50%. Even some scanners are able to minimize false positives to zero like ZeroThreat. Hence, you should prefer a tool with higher accuracy and low false positives.

Authenticated and Non-Authenticated Scans

There are two kinds of web app vulnerability scans – authenticated and non-authenticated. It’s best to pick a vulnerability scanning tool that supports both authenticated and unauthenticated scanning. A verified user can provide credentials to allow the scanner to evaluate protected pages in authenticated scanning. So, it offers deeper scanning.

Actionable Reports

Reports generated after a scan give all the information about vulnerabilities, their severity, impact, and more. A good web app scanner will provide detailed scan reports with actionable insights. These reports should provide recommendations or steps for remediating vulnerabilities discovered in the scan.

Support Scalability

A reliable free web application vulnerability scanner will adapt to your requirements as you grow. This means the tool should be able to handle increased complexity and workload. Such a tool will maintain its accuracy, efficiency, and performance even if it scans more applications than before. You can count on free tools like ZeroThreat, ZAP, and Burp Suite for excellent scalability.

Technology Independent

Web applications depend on different programming languages, frameworks, and third-party components. The tool should be able to scan applications regardless of the framework, programming languages, or other components used in your application. This will ensure that your vulnerability scanner can evaluate all kinds of web apps for vulnerabilities.

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Closing Thought

Web apps are lucrative attack targets for hackers because they are publicly available on the web and manage sensitive data. Regular security assessments are crucial to maintain a strong security posture and prevent hackers from stealing your data. Additionally, it enables your organization to adhere to regulatory compliances.

Free vulnerability scanners are a boon for organizations that cannot afford expensive tools and services, as security assessments are generally costly. These tools enable them to assess their web applications to meet their security commitment and achieve compliance without additional financial burden.

Free web app scanner ZeroThreat can help them in advanced security assessment with its next-gen spider. As an AI-powered vulnerability scanner, it can discover more complex vulnerabilities beyond OWASP top 10 and CWE 25 that most other tools fail to detect.

It’s a SaaS-based free online web application vulnerability scanner that offers automated scheduled scanning and the option to choose a preferred scanning location to protect data. It also integrates into CI/CD pipelines and existing security tools to perform vulnerability scanning within your SLDC and shift-left security.

Ready to explore more about it? Just sign up for free to see how it benefits you in real-time.