List of the Top 12 Free Web Application Firewalls (WAF) in 2025

SKUDONET offers IT executives an affordable solution that emphasizes ease of use and adaptability, ensuring optimal performance and security for IT services. With this innovative platform, you can seamlessly improve the security and reliability of your applications through an open-source ADC, allowing for significant cost savings and unparalleled flexibility within your IT framework. This approach not only streamlines operations but also empowers organizations to respond swiftly to changing technology needs.

The CacheGuard product range revolves around a foundational offering known as CacheGuard-OS. When installed on either a physical or virtual machine, CacheGuard-OS effectively converts that system into a robust network appliance. This newly formed appliance can serve multiple functions as various types of gateways that enhance the security and efficiency of your network. Below is a concise overview of the various CacheGuard appliances available. - Web Gateway: exercise control over organizational web traffic and filter out undesirable web access. - UTM (Unified Threat Management): protect your networks from a wide array of online threats using a combination of a firewall, antivirus at the gateway, VPN server, and a filtering proxy. - WAF (Web Application Firewall): prevent harmful requests from reaching your essential web applications and safeguard your enterprise. The WAF incorporates OWASP rules while allowing for the creation of custom rules, along with an IP reputation filtering system that enables the blocking of IPs identified in real-time blacklists. - WAN Optimizer: optimize the flow of your vital network traffic, conserve bandwidth, and ensure high availability for your internet connection through the use of multiple ISPs. Each appliance is designed to address specific network challenges, ultimately providing comprehensive solutions tailored to your organization’s needs.

Cloudflare serves as the backbone of your infrastructure, applications, teams, and software ecosystem. It offers protection and guarantees the security and reliability of your external-facing assets, including websites, APIs, applications, and various web services. Additionally, Cloudflare secures your internal resources, encompassing applications within firewalls, teams, and devices, thereby ensuring comprehensive protection. This platform also facilitates the development of applications that can scale globally. The reliability, security, and performance of your websites, APIs, and other channels are crucial for engaging effectively with customers and suppliers in an increasingly digital world. As such, Cloudflare for Infrastructure presents an all-encompassing solution for anything connected to the Internet. Your internal teams can confidently depend on applications and devices behind the firewall to enhance their workflows. As remote work continues to surge, the pressure on many organizations' VPNs and hardware solutions is becoming more pronounced, necessitating robust and reliable solutions to manage these demands.

Haltdos guarantees complete high availability for your website and web services through its advanced Web Application Firewall, application DDoS mitigation, Bot Protection, SSL offloading, and Load Balancing solutions, all deployed across both public and private cloud environments. It continuously monitors, identifies, and autonomously addresses a variety of cyber threats, including the OWASP top 10 vulnerabilities and Zero-day attacks, effectively eliminating the need for human involvement in the mitigation process. This proactive approach not only enhances security but also ensures that your online operations remain seamless and uninterrupted.

Introducing the leading API security platform that understands the context of the industry. Traceable detects all your APIs, assesses their risk levels, prevents API-related attacks that can result in data breaches, and offers analytics for both threat detection and investigative purposes. By utilizing our platform, you can efficiently identify, oversee, and protect every aspect of your APIs, while also enabling rapid deployment and seamless scalability to adapt to your organization's evolving requirements. This comprehensive approach ensures that your API security remains robust in the face of emerging threats.

Our technology is designed to be incredibly user-friendly while still maintaining high performance and a full range of features. We complement this with outstanding support and a commitment to fair, affordable pricing. Our solutions cater to everyone, from ambitious small startups with limited resources to large global corporations, and we appreciate each one of them! With straightforward options like Load balancing, WAF, GSLB, and SSO/Pre-Authentication, you can easily integrate our offerings. Moreover, we proudly present the only genuine ADP Application Delivery Platform that enables you to enhance both functionality and longevity through our app store or applications developed internally. This versatility ensures that all users can tailor the technology to meet their specific needs effectively.

Our cloud-based SWAP has been recognized as one of the premier defenses against threats such as cross-site scripting (XSS), SQL injection, and Distributed Denial of Service attacks. Utilizing a logic-driven approach, Cloudbric's SWAP incorporates pattern recognition, semantic analysis, heuristic evaluation, and foundational rulesets, all of which are automated and user-friendly. This level of automation eliminates the frequent need to modify security policies or update signatures. Additionally, private Web Application Firewall (WAF) deployments offer a range of customization options to meet specific needs. Our service guarantees the security of your website, ensuring it remains operational and shielded from DDoS attacks. Cloudbric takes proactive measures to thwart DDoS attacks at layers 3, 4, and 7, capable of managing threats that can surge to an impressive 20Tbps. Moreover, our solution not only offers robust protection but also enhances the overall resilience of your online presence.

MyDiamo, created by Penta Security Systems, a leading provider of encryption solutions in the Asia-Pacific region, is accessible for noncommercial purposes to everyone. For businesses and organizations that need enhanced capabilities, a commercial license can be acquired. Users can perform index searching even with column-level or partial encryption without compromising system performance. Additionally, it is designed to work seamlessly with open-source database management systems like MySQL, MariaDB, and Percona, ensuring compliance with regulations such as GDPR, PCI DSS, and HIPAA. One of its key advantages is that no code alteration is necessary, as it operates in parallel at the engine level, making it a user-friendly option for data security. Furthermore, its deployment allows organizations to maintain data integrity while implementing strong encryption measures.

Since 2011, DDoS-GUARD has established itself as a frontrunner in the realm of DDoS defense and content delivery solutions. Our unique approach utilizes our proprietary network, featuring scrubbing centers equipped with ample computational power and bandwidth to handle significant traffic loads. Unlike many competitors, we do not rely on reselling third-party services, ensuring that our offerings are genuinely our own. In today's increasingly digital landscape, cyber threats are on the rise, with a notable surge in DDoS attacks that are becoming more sophisticated, larger in scale, and more varied. To combat this evolving threat, we continually refine our traffic scrubbing algorithms, enhance our bandwidth capacities, and expand our processing resources. This proactive strategy enables us to not only shield our clients from all types of known DDoS attacks but also to identify and mitigate previously unrecognized anomalies in network activity. Our commitment to innovation ensures that we stay ahead in the fight against cyber threats.

Open-appsec is an innovative open-source project that leverages machine learning to deliver proactive security measures for web applications and APIs, safeguarding against the OWASP Top 10 vulnerabilities as well as zero-day exploits. This system can be seamlessly integrated as an add-on to Kubernetes Ingress, NGINX, Envoy, and various API Gateways. The core engine of open-appsec observes typical user interactions with your web application, utilizing this behavior data to identify any requests that deviate from established norms, subsequently forwarding these anomalies for further scrutiny to determine their potential maliciousness. To achieve this, open-appsec employs two distinct machine learning models: 1. A supervised model developed offline, drawing insights from millions of both malicious and harmless requests. 2. An unsupervised model that evolves in real time within the protected environment, focusing on the unique traffic patterns of that specific setting. In addition to its robust detection capabilities, open-appsec streamlines maintenance by eliminating the need for frequent threat signature updates and exception management, which are often prerequisites in many conventional WAF solutions. Overall, open-appsec not only enhances security but also reduces the complexity typically associated with managing web application firewalls.

ArvanCloud CDN features numerous PoP locations strategically positioned worldwide to efficiently deliver online content to users from the closest geographical point, ensuring optimal quality and speed. With the ArvanCloud Cloud Computing infrastructure, you can easily set up unlimited cloud servers within just a few clicks. Furthermore, each server allows for the creation of multiple cloud storage disks, enabling effective management of your data center communications through Firewall and the use of private or public networks. Data stored in ArvanCloud’s Cloud Storage is secured, providing peace of mind against potential data loss, and you can access a dependable storage system from virtually anywhere in the world. Additionally, ArvanCloud's Container-Based Platform as a Service adheres to Kubernetes standards, allowing you to launch an operational product with just a few simple commands, making it exceptionally user-friendly and efficient for developers. Overall, ArvanCloud's comprehensive solutions support a seamless cloud experience tailored to various needs.

BunkerWeb stands out as an innovative, open-source Web Application Firewall (WAF) tailored for the security requirements of contemporary web applications. Functioning as a full-fledged web server based on NGINX, it guarantees that your web services are "secure by default." This tool can be seamlessly integrated into diverse environments such as Linux, Docker, Swarm, and Kubernetes, and provides complete configurability via a user-friendly web interface for those who favor it over command-line interactions. In essence, BunkerWeb streamlines the intricacies of cybersecurity, making it user-friendly for everyone, regardless of their technical background. Moreover, BunkerWeb is equipped with vital security features within its core framework while also facilitating easy upgrades through a versatile plugin system, ensuring it can meet a wide array of security needs. With its adaptable architecture, users can tailor their security solutions to fit specific operational contexts, enhancing overall web protection.