Best Free Firewall Software of 2025

Enforza offers a robust cloud firewalling solution designed for enterprise needs, leveraging a cutting-edge network security platform. Our innovative approach converts Linux instances into high-performance firewall appliances equipped with advanced deep packet inspection functionalities. Key Technical Features: • Protection across Layers 4-7 with stateful inspection • Ability to create custom rules with filtering based on specific protocols • Enhanced NAT features, including SNAT and DNAT • Enforcement of security policies across different VPCs and VNETs • Minimal latency impact, measured in sub-milliseconds Enforza simplifies the complexity of firewall configurations while delivering exceptional performance compared to native cloud offerings. Experience strong firewall protection without the data processing fees often associated with AWS Network Firewall, Azure Firewall, and NAT Gateways. Safeguard your cloud infrastructure with immediate effect. For detailed technical specifications, visit enforza.com/firewall.

Monitor the volume of data your PC is using for every single app, thanks to GlassWire's network monitoring graph. Keep track of the volume of data you received and sent in the past and who or what your PC is talking to. Detect spyware, malware, badly behaving apps, and bandwidth hogs, then block their connections with our powerful firewall. Monitor devices on your network and get alerted when new unknown devices join your WiFi. GlassWire warns you of network-related changes to your PC or unusual changes to your apps that could indicate malware.

Cloudflare is the foundation of your infrastructure, applications, teams, and software. Cloudflare protects and ensures the reliability and security of your external-facing resources like websites, APIs, applications, and other web services. It protects your internal resources, such as behind-the firewall applications, teams, devices, and devices. It is also your platform to develop globally scalable applications. Your website, APIs, applications, and other channels are key to doing business with customers and suppliers. It is essential that these resources are reliable, secure, and performant as the world shifts online. Cloudflare for Infrastructure provides a complete solution that enables this for everything connected to the Internet. Your internal teams can rely on behind-the-firewall apps and devices to support their work. Remote work is increasing rapidly and is putting a strain on many organizations' VPNs and other hardware solutions.

NextDNS offers comprehensive protection from various security risks, effectively blocking advertisements and trackers across websites and applications while ensuring a secure and monitored online experience for children on all devices and networks. You can assess your security needs and customize your protection by activating over ten different safety measures. By utilizing reliable threat intelligence feeds that contain millions of harmful domains and update constantly, you can enhance your defense mechanisms. Our system goes beyond merely tracking domains; it evaluates DNS queries and responses instantaneously, allowing for the swift identification and prevention of harmful activities. Given that there is often only a brief window of hours from when a domain is registered to when it is used in an attack, our advanced threat intelligence framework is designed to identify malicious domains more efficiently than traditional security methods. Additionally, you can effectively eliminate advertisements and trackers in both websites and applications, including even the most sophisticated ones, by leveraging the most widely used ad and tracker blocklists, which include millions of domains that are refreshed in real-time. Ultimately, NextDNS empowers users with tools to create a safer browsing environment tailored to their specific security needs.

IPFire is an advanced, robust, and secure Open Source firewall built on the Linux platform. Its user-friendly interface, exceptional performance across various environments, and adaptability make it suitable for a wide range of users. Prioritizing security above all, IPFire is fortified to defend against online threats while simultaneously safeguarding your network from potential intrusions. The firewall's robust engine and its integrated intrusion prevention system work in tandem to shield your network from cyber attacks and denial-of-service threats. Developed as free software by a collaborative community, IPFire is trusted by hundreds of thousands of users globally. The core aim of IPFire is to ensure maximum security, and it is designed for easy configuration to establish a firewall engine that effectively blocks unauthorized access. By default, IPFire organizes the network into distinct zones with tailored security policies, such as LAN and DMZ, allowing for effective risk management and customized configurations to cater to specific requirements. This thoughtful design enhances the overall security posture of any network it protects.

The pfSense project provides a free network firewall distribution. It is based on FreeBSD's operating system with a custom kernel. Third-party free software packages are also included. The package system allows pfSense software to offer the same functionality as or more common commercial firewalls without any artificial limitations. It has replaced every major commercial firewall in many installations around the globe, including Check Point and Cisco PIX, Cisco ASA and Juniper.

Traditional packet filters are gradually becoming outdated, as even open-source solutions are shifting towards Next-Generation Firewalls. OPNsense stands out as a leading option for features like intrusion detection, application control, web filtering, and antivirus protection. No network, regardless of its size, is immune to potential attacks; even devices in home networks, such as washing machines and smartwatches, are at risk and need robust security measures. Firewalls play a crucial role in a comprehensive security strategy, shielding systems from both established and emerging threats. The effectiveness of a firewall is maximized when its capabilities are well understood, it operates intuitively, and is strategically placed within the network infrastructure. OPNsense rises to the occasion by fulfilling these essential requirements in various ways. This book serves as an invaluable guide for anyone looking to comprehend, install, and configure an OPNsense firewall effectively. Ultimately, understanding the intricacies of OPNsense can empower users to create a more secure digital environment.

UltraDNS is a robust, cloud-based authoritative DNS service designed for enterprises, providing reliable and swift query responses for websites and essential online resources. This managed DNS solution guarantees complete website uptime and incorporates advanced security features for enhanced protection. As users around the globe demand uninterrupted and secure digital interactions, the complexities of DNS management have escalated significantly. The rise of Internet of Things (IoT) devices, coupled with various online threats, has made it challenging for organizations to devise an effective DNS strategy tailored to their IT requirements. It is increasingly difficult to maintain a knowledgeable in-house team for DNS management, and securing the necessary resources to establish a coherent strategy that aligns with current Internet challenges is often unfeasible. Ensure your website and digital assets remain accessible at all times with UltraDNS, which is supported by a commitment to 100% uptime and top-tier service-level agreements, all on a worldwide platform. This commitment empowers businesses to focus on their core operations while trusting that their online presence is managed by experts in the field.

Xvirus Firewall is crafted as an intuitive tool that allows users to monitor all active connections and manage access permissions effectively. Utilizing a straightforward approach, Xvirus Firewall employs whitelisting and blacklisting methods to oversee connections. It lacks configurable parameters or advanced assessment features for evaluating connection legitimacy. This simplicity makes it accessible for beginners while still offering enough functionality to satisfy experienced users. Users can choose to install it and forget about it or tailor the settings for a more personalized experience, ensuring robust security regardless of their choice. Moreover, with the help of Xvirus' Network Monitor, users can access detailed information about their application's connections, including protocol, IP address, port number, connection status, and process ID. Xvirus Firewall empowers users to regulate which applications are permitted to operate on their systems. Its uncomplicated rules list allows users to easily determine which programs to allow or restrict, providing a seamless security management experience. Ultimately, Xvirus Firewall strikes a balance between usability and control, making it a valuable tool for anyone looking to enhance their system’s security.

Guardian offers the most reliable and secure method to safeguard your privacy and data while utilizing applications and surfing the internet on your iOS device. By routing traffic through its firewall servers, Guardian conceals your IP address from the websites you visit, complicating the efforts of advertisers to follow your activities. It ensures robust protection for your passwords, financial details, and other sensitive information with strong AES-256 encryption, making it difficult for hackers to access your data no matter where you are. In addition to providing an extra layer of encryption for all outgoing network traffic, Guardian also filters out unwanted junk, enhancing your mobile browsing experience. You can confidently grant permissions to specific applications on your device, knowing that any attempts to transmit data to unauthorized trackers will be effectively thwarted. Furthermore, Guardian blocks unwanted connections from location trackers, email trackers, generic data trackers, and various other online irritants, ensuring a more secure and enjoyable online presence. This comprehensive protection not only preserves your privacy but also allows you to navigate the digital world with peace of mind.

The Android Firewall is designed for immediate use and offers robust protection against hacker intrusions, alerting you whenever an application attempts to transmit data online. You will gain insight into which applications are connecting to various servers and utilizing your mobile data. With straightforward filtering options, you have the power to permit or restrict specific app connections. This firewall enables you to oversee and obstruct data traffic effectively. You also have the capability to entirely deny an app's internet access. The AI-driven Android firewall safeguards against unauthorized access from recognized intelligence agencies and government entities. Our integrated Intrusion Prevention System (IPS) automatically blocks all known servers and IP addresses associated with organizations like the FBI, CIA, NSA, and GCHQ, providing an additional layer of security. Should there be an attempt to access these blocked entities, a distinct alert will be sent to you. Firewall AI further shields you from surveillance servers located in countries such as China, Iran, and Russia, along with mobile tracking threats, ensuring your privacy remains intact and secure. In a world where data breaches are increasingly common, this firewall is an essential tool for anyone concerned about their digital safety.

Bit Guardian Firewall is a comprehensive security solution created to ensure a secure, safe, and smooth browsing experience. It provides real-time defense against harmful content by blocking unsafe URLs and filtering out undesirable websites and applications. This software features an ad-blocker that removes distracting and potentially dangerous pop-up and banner ads, allowing for a seamless browsing experience. Moreover, Bit Guardian Firewall protects user privacy by stopping online tracking, enabling users to visit their preferred websites without the anxiety of being monitored. To bolster security further, it includes additional protection with Avira's extensive malware databases, offering a formidable barrier against both online and offline threats. Designed for compatibility with Windows operating systems, this firewall is the product of Bit Guardian GmbH, a prominent software development firm headquartered in Gräfelfing, Germany. With its user-friendly interface and powerful features, Bit Guardian Firewall is an excellent choice for individuals seeking reliable online protection.

Comodo Advanced Endpoint Protection delivers an exceptional anti-malware suite that actively safeguards your servers, workstations, laptops, and netbooks, while also providing sophisticated, real-time oversight and management of essential system resources. It can be utilized either as a comprehensive security package or as a standalone sandbox to enhance existing antivirus solutions, making Comodo ESM a top choice for endpoint protection on Microsoft Windows servers, desktops, laptops, and tablets. The complete Comodo Endpoint Security suite boasts five layers of defense—Antivirus, Firewall, Host Intrusion Prevention, Auto-Sandbox, and File Reputation—directly at the user level on the desktop. Its innovative auto-sandbox technology effectively prevents malware infections and operating system damage by executing untrusted processes in a segregated environment. Furthermore, Comodo's endpoint protection is distinguished as the only managed anti-malware solution that offers a limited warranty of $5,000 against malware infections, affirming its commitment to security. This combination of advanced features ensures that users have a robust and reliable defense against evolving cyber threats.

Sophos UTM elevates threat prevention to unprecedented heights. At the core of Sophos Sandstorm is an advanced deep learning neural network, a sophisticated type of machine learning that effectively identifies both familiar and unfamiliar malware without depending on traditional signatures. Notably, Sophos UTM 9.4 stands out as one of the pioneering products to incorporate our state-of-the-art next-gen cloud sandboxing technology. Sandstorm significantly enhances protection against ransomware and targeted attacks while providing comprehensive visibility and analytical capabilities. It swiftly and accurately detects evasive threats before they infiltrate your network. Furthermore, it delivers exceptional value by offering enterprise-quality protection without the burden of exorbitant costs or complexities. You can fortify your web servers and Microsoft Enterprise Applications against cyber threats while ensuring secure access for external users through reverse proxy authentication. Additionally, our unique all-in-one solution guarantees complete SMTP and POP message protection from spam, phishing attempts, and data breaches, enhancing your overall cybersecurity posture. Ultimately, Sophos UTM equips businesses with robust tools to safeguard their digital assets effectively.

Azure Firewall serves as a cloud-managed network security solution designed to safeguard your Azure Virtual Network assets. This service operates as a fully stateful firewall, ensuring both high availability and scalable performance in the cloud environment. It is a comprehensive network security tool that not only protects your resources but also allows for the creation, enforcement, and logging of connectivity policies across various subscriptions and virtual networks. With its robust features, you can streamline the deployment and management of network security, taking advantage of the firewall's scalability and availability. Additionally, it enables centralized management of security settings across multiple virtual networks, employing a unified set of application and network rules for enhanced protection. This makes it easier for organizations to maintain consistent security postures as they expand their cloud infrastructure.

Google Cloud firewalls are intricately integrated into the cloud networking structure, offering scalability and precision to cater to the specific security requirements of your business. They provide a versatile and customizable approach, allowing you to implement protection at various levels, including organization, folder, and project, while maintaining flexible control over your firewall rules and policies. Additionally, you can enhance your security management through visibility and optimization features, which offer valuable insights into the usage of firewall rules and highlight potential areas for improvement. Furthermore, with the use of network tags and service accounts, you can establish detailed controls that effectively manage both north-south and east-west traffic, ensuring comprehensive security across your network. This multifaceted approach not only fortifies your defenses but also simplifies the overall management of your cloud environment.

Open source software and a universal router are key to democratizing the way we access networks. VyOS' vision is to revolutionize how we access networks, so that everyone can build the solutions they have always wanted, without limitations, restrictions, or prohibitive prices. We believe that internet access is just as important to human development as food, water, air, and healthcare. VyOS was founded by engineers for engineers. It is an open-source software company that makes it possible to access networks without restrictions or prohibitive fees. Through our open-source software and virtual platforms, we do this as VyOS. Stateful firewalls, zone based firewall, all types source and destination NAT (one-to-one, one-to many, many to many). For auditing, creating customized images and contributing, everyone has access to the entire codebase and build toolchain.

AP Lens is a Sandbox Browser designed to enhance network security through DNS Whitelisting, effectively preventing attacks from penetrating the network. What features does AP Lens offer? - Web Filtering: Offers adaptable and user-friendly options for content blocking. - Anti-Phishing: Eliminates look-alike domains with complete precision. - Ransomware Protection: Safeguards the network while allowing business applications to function smoothly. - Secure Remote Work: Implements internet usage policies efficiently without the delays associated with VPNs. - No More 0-Day Attacks: Overcomes the limitations of traditional blacklisting through the AP Lens Augmented Whitelist. - Compliant: Aligns with regulatory standards set forth by cybersecurity insurance policies. - One-Click Installation: Allows for quick setup without requiring extensive user intervention or updates. - No Maintenance: Prevents malware and phishing threats without the need for ongoing oversight. With a foundation built on over 20 years of expertise in cybersecurity, cloud security, and information protection across various sectors, including private banking and public services, our team is equipped to address the evolving challenges in digital security.

m0n0wall is an initiative focused on developing a comprehensive, embedded firewall software solution that, when paired with an embedded PC, delivers all essential features found in commercial firewall devices, including user-friendliness, at a significantly lower cost, being free software. This project utilizes a minimal version of FreeBSD, incorporating a web server, PHP, and several other utilities, with the entire system's configuration maintained in a single XML text file to ensure clarity and simplicity. Notably, m0n0wall is likely the first UNIX-based system to implement its boot-time configuration using PHP instead of the traditional shell scripts, and it uniquely stores all system configurations in XML format, showcasing an innovative approach in firewall technology. This distinct method enhances both usability and manageability, marking a significant advancement in the realm of open-source firewall solutions.

CrowdSec, a free, open-source, and collaborative IPS, analyzes behaviors, responds to attacks, and shares signals across the community. It outnumbers cybercriminals. Create your own intrusion detection system. To identify cyber threats, you can use behavior scenarios. You can share and benefit from a crowdsourced, curated cyber threat intelligence platform. Define the type and location of the remediation you wish to apply. Use the community's IP blocklist to automate your security. CrowdSec can be run on containers, virtual machines, bare metal servers, containers, or directly from your code using our API. Our cybersecurity community is destroying cybercriminals' anonymity. This is our strength. You can help us create and distribute a qualified IP blocklist that protects everyone by sharing IP addresses you have been annoyed by. CrowdSec can process massive amounts of logs faster than Fail2ban, and is 60x faster than Fail2ban.