Best Free Web Application Firewalls (WAF)

CacheGuard-OS transforms a virtual or bare metal machine into a powerful and easy to handle network appliance. It's a Linux based Operating System built from scratch and especially designed to Secure and Optimize the network traffic. Great care has been taken by CacheGuard-OS developers to select the best of the best Open Source technologies to integrate into CacheGuard-OS. The result is a robust and trustworthy solution that can be up and running within minutes. CacheGuard-OS integrates Open Source software such as but not limited to OpenSSL, NetFilter, IProute2, StrongSwan, ClamAV, Apache, ModSecurity, Squid and Open Source developments made by CacheGuard-OS developers.

Cloudflare is the foundation for your infrastructure, applications, and teams. Cloudflare secures and ensures the reliability of your external-facing resources such as websites, APIs, and applications. It protects your internal resources such as behind-the-firewall applications, teams, and devices. And it is your platform for developing globally scalable applications. Your website, APIs, and applications are your key channels for doing business with your customers and suppliers. As more and more shift online, ensuring these resources are secure, performant and reliable is a business imperative. Cloudflare for Infrastructure is a complete solution to enable this for anything connected to the Internet. Behind-the-firewall applications and devices are foundational to the work of your internal teams. The recent surge in remote work is testing the limits of many organizations’ VPN and other hardware solutions.

Reliable, Scalable, and Secure Load Balancing Formerly known as Zevenet, SKUDONET Enterprise Edition is an advanced and highly scalable Open Source Application Delivery and Security Platform designed to handle large volumes of traffic across any environment—whether physical, virtual, or cloud-based for modern IT infrastructures. Built on the Linux Debian system, SKUDONET offers a robust platform that integrates advanced security and performance features, offering a cost-effective alternative to other solutions on the market. Key Features & Benefits: ✔ High Availability – Prevents downtime with intelligent traffic balancing and clustering ✔ Advanced Security – Includes DoS protection, SSL offloading, and L7 filtering to enhance cybersecurity ✔ High Scalability – Multi-core processing, optimized packet handling, and support for high-throughput environments ✔ Flexible Deployment – Available for bare metal, virtual machines, and cloud platforms with BYOL (AWS, DigitalOcean)

Haltdos promises an intelligent WAF & DDoS mitigation service with multi-layered security to online businesses requiring zero management. It is a self-learning solution that continuously learns and adapts network/website traffic and provides real-time and historical insights with stunning visualization. It also provides attack alerts and notifications, attack signatures, customer misbehavior, and audit trail.

Meet the Industry’s Context-Aware API Security Platform Traceable identifies all of your APIs, and evaluates your API risk posture, stops API attacks that lead to incidents such as data exfiltration, and provides analytics for threat hunting and forensic research. With our solution, you can confidently discover, manage and secure all of your APIs, quickly deploy, and easily scale to meet the ongoing needs of your organization. If you’re planning on improving the data security posture in your APIs, Traceable would love the opportunity to discuss how we could help and share some of our lessons learned from working with enterprise customers like Canon, Informatica, Outreach, and many others.

SafeLine WAF is a self-hosted, semantic-based Web Application Firewall developed by the team at Chaitin Technology. It focuses on protecting web applications from a wide range of threats, especially zero-day and application-layer (Layer 7) attacks, with high precision and minimal false positives. It is open source, easy to deploy, and designed to be flexible enough for both enterprise and personal use.

Choose us because we offer the easiest to use technology without sacrificing features or performance. We back this up with outstanding support and care, delivered under a fair and cost effective pricing model Our technology is used by the smallest startups with big ideas and small budgets all the way to global enterprises and anything in between. We love them all the same! Easy to use Load balancing, WAF, GSLB and SSO/Pre-Authentication. It is also the Only true ADP Application Delivery Platform where the functionality and lifespan can be enhanced using the app store or applications that you develop in house.

Our cloud SWAP has been vetted to be one of the most comprehensive solutions against threats such as cross-site scripting (XSS), SQL injections, and Distributed Denial of Service (DDoS). Cloudbric’s patented logic-based SWAP (featuring pattern matching, semantic, and heuristic analysis) and core rulesets are fully automated and easy to use. Meaning, is no need for frequent signature updates or complicated configuration of security policies. Customization options are also available for private WAF deployments. Our service ensures your website. will stay online and be protected against distributed denial of service attacks (DDoS). Cloudbric actively blocks layers 3, 4, and 7 DDoS attacks scalable up to 20Tbps. Cloudbric is a fully managed cybersecurity service with policy optimization, malicious traffic monitoring, DDoS protection, online real-time dashboard and 24/7 technical support.

Developed by Penta Security Systems, an APAC leader in encryption technology and web application firewall, MyDiamo is a free open-source database encryption solution, available to all for non-commercial use. The commercial license is available for enterprises and organizations that desire extended features.

WEDOS Protection is a modern security solution combining powerful DDoS mitigation, CDN acceleration, and intelligent traffic filtering — designed for high availability, stability, and optimal web performance. It protects serious online businesses against volumetric and sophisticated application-layer attacks, including botnets and L7 exploits. Our global infrastructure WEDOS Global uses edge servers distributed worldwide to analyze and control traffic in real time. The service provides DNS protection, an advanced Web Application Firewall (WAF), HTTPS proxy, smart caching, anti-bot filters, and multiple protection layers that together form a robust security and performance ecosystem. ✅ Effective L3–L7 DDoS mitigation ✅ Global content acceleration via proprietary network ✅ Easy to implement – no code changes needed ✅ High availability and low latency even during attacks An ideal choice for high-traffic websites, ecommerce projects, agencies, and hosting providers.

DDoS-GUARD is one of the leading service providers on the global DDoS protection and content delivery markets since 2011. Unlike most of other companies, we provide services using our own network of scrubbing centers having sufficient channel and computing capacities to process high volumes of traffic. We do not resell other companies' services claiming them as our own. Today's digital world shows us ever-increasing number of cyber threats. Abreast of the latest trends, the number of DDoS attack types is increasing too. Besides, the attacks themselves become more volumetric, complex and varied. Realizing that, we are constantly modifying traffic scrubbing algorithms, increasing channel capacity, add computational resources to traffic processing centers. It allows us not only provide protection against all known DDoS attack types to our customers, but also detect and block any previously unknown anomalous network activity.

automatic web application & API security using machine learning open-appsec is an open-source initiative that builds on machine learning to provide pre-emptive web app & API threat protection against OWASP-Top-10 and zero-day attacks. It can be deployed as add-on to Kubernetes Ingress, NGINX, Envoy and API Gateways. open-oppsec simplifies maintenance as there is no threat signature upkeep and exception handling, like common in many WAF solutions.

ArvanCloud CDN comprises tens of PoP sites in important locations all around the world to deliver online content to the users, from the closest geographical point at the highest speed and quality. With ArvanCloud Cloud Computing infrastructure, you are just a few clicks away from creating unlimited cloud servers on demand. You can create several cloud storage disks for each server and easily manage your cloud data center communications using Firewall and private and public networks. ArvanCloud allows you to save any kind of data on Cloud Storage in a completely encrypted format. You can have stable access to a reliable storage system from all around the world, without worrying about data loss. With ArvanCloud container-based Platform as a Service, which conforms to Kubernetes standards, you are just a few commands in CLI away from an operational product.

BunkerWeb is a next-generation and open-source Web Application Firewall (WAF). Being a full-featured web server (based on NGINX under the hood), it will protect your web services to make them "secure by default". BunkerWeb integrates seamlessly into your existing environments (Linux, Docker, Swarm, Kubernetes, …) and is fully configurable (don't panic, there is an awesome web UI if you don't like the CLI) to meet your own use-cases . In other words, cybersecurity is no more a hassle. BunkerWeb contains primary security features as part of the core but can be easily extended with additional ones thanks to a plugin system).