OPNsense vs Palo Alto Networks K2-Series comparison

OPNsense and Palo Alto Networks are both solutions in the Firewalls category. OPNsense is ranked #3 with an average rating of 7.9, while Palo Alto Networks is ranked #36 with an average rating of 8.7. OPNsense holds a 11.0% mindshare in Firewalls, compared to Palo Alto Networks’s 0.1% mindshare. Additionally, 95% of OPNsense users are willing to recommend the solution, compared to 96% of Palo Alto Networks users who would recommend it.

Comparison Buyer's Guide

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Executive SummaryUpdated on Sep 16, 2024

OPNsense and Palo Alto Networks K2-Series are both prominent firewall solutions catering to different user needs. Users appreciate the pricing and support of OPNsense, while many find that despite its higher cost, Palo Alto Networks K2-Series offers superior features justifying the investment.

Features: OPNsense's flexibility and open-source nature allow extensive customization. The active community contributes to its development, ensuring a wide range of plugins. Its ease of integration with other systems is beneficial to users. Palo Alto Networks K2-Series offers advanced threat detection, which many consider state-of-the-art. Its automated security measures ensure proactive protection. Comprehensive compliance features help businesses adhere to industry standards.

Room for Improvement: OPNsense users highlight the need for better documentation. The interface could be more user-friendly, and the learning curve is often steep for beginners. Additionally, enhancing the scalability of the platform would benefit larger enterprises. Palo Alto Networks K2-Series users note a steep learning curve. Simplifying the management processes would improve user experience. They also desire more intuitive reporting tools to better understand security metrics.

Ease of Deployment and Customer Service: OPNsense is praised for its straightforward deployment process. The active community support is a major advantage. Its deployment is often quicker, requiring less technical expertise. Palo Alto Networks K2-Series, while powerful, requires significant expertise for deployment and configuration. Extensive customer service and support resources provide assistance once it is set up. Users find the initial setup challenging but beneficial in the long run.

Pricing and ROI: OPNsense is often chosen for its cost-effectiveness. Lower setup costs make it accessible for smaller businesses. The open-source model reduces overall expenses. Palo Alto Networks K2-Series involves higher initial expenses. It is viewed as a valuable long-term investment due to its security advantages. The advanced features justify the higher cost for those seeking robust security. The return on investment is significant through reliability and advanced protection.

To learn more, read our detailed OPNsense vs. Palo Alto Networks K2-Series Report (Updated: September 2025).

Buyer's Guide

OPNsense vs. Palo Alto Networks K2-Series

September 2025

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Review summaries and opinions

We asked business professionals to review the solutions they use. Here are some excerpts of what they said:

Categories and Ranking

Fortinet FortiGate

Mindshare comparison

As of October 2025, in the Firewalls category, the mindshare of Fortinet FortiGate is 20.4%, up from 19.1% compared to the previous year. The mindshare of OPNsense is 11.0%, down from 15.1% compared to the previous year. The mindshare of Palo Alto Networks K2-Series is 0.1%, up from 0.0% compared to the previous year. It is calculated based on PeerSpot user engagement data.

Firewalls Market Share Distribution
Product	Market Share (%)
Fortinet FortiGate	20.4%
OPNsense	11.0%
Palo Alto Networks K2-Series	0.1%
Other	68.5%

Firewalls

Featured Reviews

Vasu Gala

Manager, Information Technology Operation/Presales at TechMonarch

A stable solution with an intuitive interface and quick customer service

I have been working with Fortinet FortiGate, WatchGuard, Sophos, and SonicWall. I'm not as comfortable with SonicWall because of their UI and limitations. I prefer Fortinet above all other options. When it comes to configuration, I am confident in my ability to handle various tasks, including creating policies such as firewall rules, web policies, and application policies. Additionally, I can configure VPNs and implement load balancing, among other tasks. Overall, I feel much more comfortable working with Fortinet. Fortinet has made significant improvements by integrating AI with firewalls for threat analysis and prevention. In the past 2-3 years, they have launched FortiSASE and SIEM, and they also provide SOC services. Both Palo Alto and Fortinet FortiGate are excellent. While Fortinet FortiGate comes at higher prices, the functionality and support justify the cost. They promptly resolve firmware issues and inform all support providers about configuration changes.

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Moutaz Sheikh Alard

ISO 27001 Lead Implementer at a consultancy with 11-50 employees

Has helped simulate enterprise security setups and strengthens network segmentation practices

For my capstone, I use OPNsense for my project and its broader benefits for enterprise and cybersecurity context. OPNsense is an open source based firewall and routing platform. It offers enterprise-grade features such as intrusion detection and prevention system, VPN support, traffic shaping, and web filtering, all without license cost. This platform has a modular design, a clean web-based GUI, and frequent updates that prioritize security and usability. It competes with commercial firewalls such as Cisco ASA, FortiGate, and Palo Alto, but stands out because it's community-driven, cost-effective, and transparent. I find OPNsense's feature of acting as a central firewall and gateway most valuable, providing robust point segmentation between the internal network and DMZs in my capstone project, intrusion detection to monitor malicious traffic, VPN services for secure remote access, and logging and monitoring for compliance and auditing. This allows me to simulate a real-world enterprise environment on a smaller scale, demonstrating both security hardening and network efficiency. OPNsense impacts my projects and home network positively because its cost-effectiveness is perfect for lab and enterprise setup without expensive licensing. The flexibility, easy VLAN and DMZ configuration supports different zones such as web servers, mail servers, and log servers. The security-first design for IDS/IPS integration helps me showcase modern defense-in-depth strategies. The user-friendly management through the web GUI makes it possible to manage complex firewall rules clearly, which is critical when documenting and presenting a capstone. Scalability is also an advantage. Although my project is lab-based, OPNsense can scale into production deployments in SMBs and enterprise.

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Krishnakumar M

enterprise architect at a tech services company with 1-10 employees

One of the best tools for the prevention of evasive threats

There is a feature called granular application controls, which I liked. Instead of relying on ports and IP addresses, they use AMP ID. This kind of solution is very good. Another valuable feature is the prevention of evasive threats, which is one of the best tools I've encountered. SSL decryption and app ID-based SSL decryption are also impressive, along with the integration with user ID. Identity-based policies ensuring only authorized users can access specific resources are excellent features. Normally, there is something called SIM or SCIM in IDA IDM, but this feature is provided on the box, which is exemplary.

Read full review

Quotes from Members

We asked business professionals to review the solutions they use. Here are some excerpts of what they said:

Pros

"This solution made it very easy to manage our bandwidth."

"Secure, user-friendly, stable, and scalable network security solution. Installation is straightforward."

"Its user interface is good, and it is always working fine."

"Its usability is good. We can easily navigate the system, and we have a very good user experience."

"The most valuable feature is the bundled subscription, which is IPS, TV and web filtering."

"The most valuable features of Fortinet FortiGate IPS are firewall and filtering."

"It offers web filtering capabilities at a more affordable price compared to other solutions like PSMs or NETGEAR."

"The most valuable feature of the solution revolves around SSL VPN."

More Fortinet FortiGate pros

"We have been operating here in our lab for several months, and everything appears to be extremely stable."

"It's more secure and more reliable."

"Overall, I would rate OPNsense as nine out of ten."

"The solution is good for a basic firewall for a small business or for home use."

"The system in general is quite flexible."

"It has firewall and VPN capabilities, which are very valuable features."

"It has an open license. It works very well, and there is an update every month."

"We have found pretty much all the features of the solution to be valuable."

More OPNsense pros

"It's easy to configure."

"This is a very reliable firewall and we have never had problems with it."

"Everything I could possibly want has already been implanted in the new version."

"The most valuable features are the virtualization of the firewall and the antivirus."

"K2-Series' best features include its scalability, which is the best on the market."

"The solution offers effective security features such as HIDS (Host-based Intrusion Detection System) in global products."

"Overall product rating: Nine out of ten."

"The solution is reliable and scales well."

More Palo Alto Networks K2-Series pros

Cons

"In the past six to seven years with the Fortinet FortiGate, we've had two major downtimes, both caused by firmware upgrades."

"The issue with Fortinet FortiGate is the many security CVEs around; I have read there are probably multiple critical CVEs above 9.0 in Fortinet FortiGate products."

"The anti-malware engine could use an upgrade."

"Application management can be improved."

"WAN load-balancing could be a lot better at detecting when a link is poor or inconsistent, and not just flat out dead."

"Fortinet Fortigate could benefit by simplifying some of their processes."

"A sandbox would be good in order to be able to inspect the emails containing spam and be able to validate the emails that contain malware, prior to delivering to the customer."

"The UTM filtering needs improvement."

More Fortinet FortiGate cons

"The logging could improve in OPNsense."

"The interface needs to be simplified. It is not user-friendly."

"The interface of the solution is an area with shortcomings."

"The support for OPNsense is good because we have documents available on the internet. The support could improve a little."

"SD-WAN (software-defined wide area network) is integrated into some restricted service providers for OPNSense."

"OPNsense showed me some problems when using it in different environments. The problem is integration with a virtual server."

"pfSense has better performance and quicker updates."

"The only thing that I would like to see improved is the Insight or the NetFlow analysis part. It would be good to have the possibility to dig down on the Insight platform. Right now, we can easily do only a few analyses. If this page becomes more powerful, it surely will be a well-adopted platform."

More OPNsense cons

"The scalability of Palo Alto Networks K2-Series is good. It is good for larger environments over smaller ones."

"I would like to see the threat intelligence capability integrated with other vendors such as Cisco and Forcepoint."

"Palo Alto doesn't have extended visibility to the end point in their firewalls."

"In the past, we've had trouble with Palo Alto's application filtering not getting it right. I would not be recommending layer 7 application filtering yet."

"The ease of management and configuration should be improved."

"The reporting functionality in GlobalProtect needs to be improved."

"The solution's commitment time could be reduced as it often takes a lot of time to execute."

"It would be really helpful to have dashboards that provide information on IOC blockings such as where and how many. It will also be good to know how many hashing files have been reported. It would also be nice to have easy access to this information. Otherwise, it's a painful, manual task."

More Palo Alto Networks K2-Series cons

Pricing and Cost Advice

"The pricing for this solution is reasonable."

"The pricing is perfect."

"Fortinet FortiGate is reasonably priced."

"It's very competitive."

"Fortinet FortiGate allows you to purchase licenses for hardware and software."

"I'll rate FortiGate's pricing a five out of ten since it is moderately priced."

"The price of Fortinet FortiGate when compared to other solutions is high. However, my knowledge of the price is from third parties and I am not sure how accurate it is. I typically work in the technical area of my organization."

"It could be more competitive and cost-effective."

More Fortinet FortiGate pricing and cost advice

"It costs about $1000."

"The solution is not expensive."

"It is open source and free."

"We are not paying any licensing fees. OPNsense is completely free for us."

"The price of OPNsense is good."

"I would rate the pricing a nine out of ten, especially considering the availability of a free community edition."

"OPNsense is open source software so at this time it is free for us to use."

"Its pricing is unbeatable in comparison to other firewalls. You can have a small instance that could be €80 a month with the hardware underneath. Azure Firewall and FortiGate are out of the question at this price. If you are on a public cloud, you need the underlying infrastructure. Other than that, there is no additional cost. If you have it on-prem, you have to buy the server or the appliance. The hardware cost is replaced with the infrastructure cost in the cloud. You also have costs for the public IPs and underlying VMs, but that's not related to OPNsense. It would be the same for a FortiGate deployment on Azure. You need a FortiGate license, and you need the underlying infrastructure that scales up depending on your needs."

More OPNsense pricing and cost advice

"The overall price of Palo Alto Networks K2-Series could be reduced."

"Pricing is a sensitive issue because the cost is high in this market."

"If you compare K2-Series' quality with its price, I think it is reasonable."

"Palo Alto firewalls are very expensive."

"This solution is expensive compared to other, similar products."

"It would be nice if they lowered their prices for small businesses."

"We are on an annual license to use Palo Alto Networks K2-Series."

"The price of this solution is too high."

More Palo Alto Networks K2-Series pricing and cost advice

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Top Industries

By visitors reading reviews

Computer Software Company

15%

Comms Service Provider

Manufacturing Company

Financial Services Firm

Computer Software Company

16%

Comms Service Provider

16%

University

Educational Organization

Performing Arts

24%

Computer Software Company

16%

Manufacturing Company

Comms Service Provider

Company Size

By reviewers

Large Enterprise

Midsize Enterprise

Small Business

By reviewers
Company Size	Count
Small Business	350
Midsize Enterprise	130
Large Enterprise	187

By reviewers
Company Size	Count
Small Business	30
Midsize Enterprise	5
Large Enterprise	8

By reviewers
Company Size	Count
Small Business	13
Midsize Enterprise	8
Large Enterprise	13

Questions from the Community

Which is the better NGFW: Fortinet Fortigate or Cisco Firepower?

When you compare these firewalls you can identify them with different features, advantages, practices and usage a...

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What is the biggest difference between Sophos XG and FortiGate?

From my experience regarding both the Sophos and FortiGate firewalls, I personally would rather use FortiGate. I know...

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What are the biggest technical differences between Sophos UTM and Fortinet FortiGate?

As a solution, Sophos UTM offers a lot of functionality, it scales well, and the stability and performance are quite ...

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What is the difference between PfSense and OPNsense?

Two of the most common and well recognized firewalls, PfSense and OPNsense both support site-to-site IPsec VPN and cl...

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What do you like most about OPNsense?

What I like the most about OPNsense is that it offers an easy-to-use dashboard for device management and control.

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What is your experience regarding pricing and costs for OPNsense?

My experience with pricing, setup cost, and licensing is that since OPNsense is free, the licensing and setup was eas...

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Features comparison between Palo Alto and Fortinet firewalls

In the best tradition of these questions, Feature-wise both are quite similar, but each has things it's better at, it...

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What is your experience regarding pricing and costs for Palo Alto Networks K2-Series?

The pricing for the Palo Alto Networks K2-Series solution is affordable and there are no complaints about the licensing.

See all answers

What needs improvement with Palo Alto Networks K2-Series?

The graphical user interface is a little complex and difficult to manage. L1 engineers cannot work on the Palo Alto N...

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Comparisons

Sophos XG vs Fortinet FortiGate

Compared 17% of the time

Cisco Secure Firewall vs Fortinet FortiGate

Compared 11% of the time

Netgate pfSense vs Fortinet FortiGate

Compared 9% of the time

Cisco Meraki MX vs Fortinet FortiGate

Compared 4% of the time

WatchGuard Firebox vs Fortinet FortiGate

Compared 4% of the time

More Fortinet FortiGate Competitors

Netgate pfSense vs OPNsense

Compared 38% of the time

IPFire vs OPNsense

Compared 14% of the time

Sophos XG vs OPNsense

Compared 8% of the time

Untangle NG Firewall vs OPNsense

Compared 3% of the time

Sophos XGS vs OPNsense

Compared 3% of the time

More OPNsense Competitors

Cisco Secure Firewall vs Palo Alto Networks K2-Series

Compared 52% of the time

Juniper SRX Series Firewall vs Palo Alto Networks K2-Series

Compared 48% of the time

More Palo Alto Networks K2-Series Competitors

Product Reports

Buyer's Guide

Fortinet FortiGate

October 2025

Download Fortinet FortiGate product report

Buyer's Guide

OPNsense

September 2025

Download OPNsense product report

Buyer's Guide

Palo Alto Networks K2-Series

September 2025

Download Palo Alto Networks K2-Series product report

Overview

Fortinet FortiGate excels in providing integrated VPN, firewalling, and Unified Threat Management (UTM) with centralized management and high availability. It supports remote access and comprehensive threat protection, making it a preferred choice for securing networks.

Fortinet FortiGate offers a robust security platform with features such as strong intrusion prevention, application control, and web filtering. Its integration with Active Directory and SD-WAN functionality provides scalable solutions for large networks. Users appreciate its ease of use through centralized management interfaces, ensuring robust security with flexible configurations. However, FortiGate could enhance its graphical interface and technical support responsiveness, address firmware bugs and costly licensing, improve logging, integrate better with third-party tools, and strengthen scalability and memory for log storage. Complexity in configuration and the need for intuitive features are noted challenges, and there's a demand for advanced security, zero-trust capabilities, and AI integration.

What are the key features of Fortinet FortiGate?

VPN: Secure remote access and connectivity.
Firewalling: Protects networks from unauthorized access and attacks.
UTM: Offers a comprehensive approach to threat management.
SD-WAN: Optimizes traffic routing for efficient network performance.
Web Filtering: Controls and monitors web access and ensures Internet security.

What benefits or ROI should be considered?

Centralized Management: Simplifies administration and monitoring.
High Availability: Ensures consistent security and network availability.
Scalability: Adapts to the needs of growing networks.
Comprehensive Threat Protection: Provides robust security measures.
Ease of Use: Minimizes the complexity of security management.

Fortinet FortiGate is widely implemented across industries like education, finance, and government. Companies use it for firewall protection, VPN, and SD-WAN capabilities, ensuring secure perimeter and data center security. It facilitates remote access management and traffic routing optimization, offering reliable security and connectivity solutions.

Fortinet

OPNsense is an adaptable open-source firewall and routing platform appreciated for its flexibility, scalability, and user-friendly interface. It is equipped with robust security features and offers excellent reporting and visibility, essential for small businesses and home setups.

OPNsense stands out for its modular design, allowing cost-effective customization. This system supports VPNs and various firewall capabilities, making it suitable for securing networks from malicious traffic. Its frequent updates and extensive documentation, combined with a supportive online community, enhance user experience. However, there is room for improvement in integration with virtual servers and Azure. Scalability and hardware updates are important for large-scale environments, and users desire more reliable VPN solutions and enhanced threat intelligence tools.

What are OPNsense's most important features?

Flexibility: Easily customizable due to its open-source nature.
Robust Security: Advanced security features for network protection.
User-Friendly Interface: Simplified management and configuration.
Frequent Updates: Regular improvements and new features.
Dense Documentation: Extensive resources and community support.

What benefits should users look for in reviews?

Cost-Effectiveness: Open-source design reduces costs.
Scalability: Ability to grow with business needs.
Customizability: Tailored solutions for different requirements.
Community Support: Access to a strong network of resources and peers.

OPNsense is implemented in industries requiring VPN and firewall functions, supporting site-to-site connections, protecting servers, and managing commercial network traffic. Companies apply it for security, UTM, SD-WAN, content filtering, intrusion detection, and prevention, utilizing its open-source nature and effectiveness as a next-generation firewall.

OPNsense

Designed to handle growing throughput needs due to increasing amounts of application-, user-, and device-generated data, the K2-Series offers amazing performance and threat prevention capabilities to stop advanced cyberattacks and secure mobile network infrastructure, subscribers, and services.

Palo Alto Networks

Sample Customers

Amazon Web Services, Microsoft, IBM, Cisco, Dell, HP, Oracle, Verizon, AT&T, T-Mobile, Sprint, Vodafone, Orange, BT Group, Telstra, Deutsche Telekom, Comcast, Time Warner Cable, CenturyLink, NTT Communications, Tata Communications, SoftBank, China Mobile, Singtel, Telus, Rogers Communications, Bell Canada, Telkom Indonesia, Telkom South Africa, Telmex, Telia Company, Telkom Kenya

1. Deciso B.V. 2. iXsystems, Inc. 3. EuroBSDCon 4. Netgate 5. Claranet 6. Voleatech 7. Open Systems AG 8. Securebit AG 9. Proxmox Server Solutions GmbH 10. AVM Computersysteme Vertriebs GmbH Additional customers include: T-Systems International GmbH, Deutsche Telekom AG, Vodafone GmbH, 1&1 IONOS SE, OVHcloud, Hetzner Online GmbH, Strato AG, PlusServer GmbH, Host Europe GmbH, United Internet AG, 1&1 Versatel Deutschland GmbH, QSC AG, Bechtle AG, Cancom SE, Computacenter AG & Co. oHG, T-Systems Multimedia Solutions GmbH, Atos SE, Capgemini SE, Accenture plc, IBM Corporation, Hewlett Packard Enterprise Company, Cisco Systems, Inc.

State of North Dakota, SEGA, Alameda County Office of Education, Temple University, VERGE, CAME

Buyer's Guide

OPNsense vs. Palo Alto Networks K2-Series

September 2025

Free Report: OPNsense vs. Palo Alto Networks K2-Series

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