Fortinet FortiOS vs OPNsense comparison

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Fortinet FortiOS

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Executive SummaryUpdated on Sep 16, 2024

Fortinet FortiOS and OPNsense are two leading firewall options. Fortinet FortiOS has the upper hand due to its robust security features.

Features: Fortinet FortiOS offers advanced threat protection, integrated threat intelligence, and comprehensive security features. OPNsense is appreciated for its open-source nature, customizable options, and extensive plugins.

Room for Improvement: Fortinet FortiOS users have noted its complexity and higher learning curve. OPNsense could improve in stability and adding more features. FortiOS would benefit from a more user-friendly approach. OPNsense needs a more robust performance.

Ease of Deployment and Customer Service: Fortinet FortiOS has a straightforward deployment process and professional customer support. OPNsense receives mixed reviews regarding deployment but benefits from active community support.

Pricing and ROI: Fortinet FortiOS involves higher setup costs but provides high returns due to strong security measures. OPNsense, being an open-source solution, offers lower initial costs and a satisfactory ROI for cost-sensitive users.

To learn more, read our detailed Fortinet FortiOS vs. OPNsense Report (Updated: August 2026).

Fortinet FortiOS vs. OPNsense

August 2026

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Helped 908,858 peers since 2012

Review summaries and opinions

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

ROI

Sentiment score

6.3

Fortinet FortiOS offers cost-effective, scalable security, with competitive pricing and partnerships, enhancing ROI compared to top brands.

Sentiment score

3.0

Numerous users reported substantial financial savings and improved network security with OPNsense compared to alternatives like FortiGate or Sophos.

Once it is deployed, I do not have to revisit or replace the hardware.

Network Administrator at a educational organization with 501-1,000 employees

The pricing of FortiOS is competitive and reasonable compared to other leading products such as Palo Alto and Check Point.

Senior Manager at ITX360 (Pvt) Ltd

Fortinet is strong in terms of cost and compatibility with other vendors.

For more quotes and insights, download the Fortinet FortiOS report

Technology Consultant at NetWiser

The network attacks reduced by approximately 60% after using that, even without customizing the custom configuration yet.

Mahmoud Suleiman

Senior IT Infrastructure Engineer at a real estate/law firm with 11-50 employees

For a very little investment, I was able to increase the security of my network.

For more quotes and insights, download the OPNsense report

Administrator at a retailer with 10,001+ employees

Customer Service

Sentiment score

8.2

Fortinet FortiOS support is responsive and helpful but sometimes slow with complex issues, lacking top-tier vendor standards.

Sentiment score

5.3

OPNsense users mostly find community forums and documentation sufficient, though some express dissatisfaction with official support availability and cost.

I would rate them nine or ten out of ten.

Technology Consultant at NetWiser

Fortinet technical support is very responsive and helpful.

For more quotes and insights, download the Fortinet FortiOS report

Senior Manager at ITX360 (Pvt) Ltd

Support engineers sometimes lack eagerness to assist with issues such as the memory problem.

Mitku Bitew

Director, IT Infrastructure Department at Zemen Bank S.C.

Compared to some open-source projects with weak support, OPNsense stands out for having both a strong community and commercial backing options.

For more quotes and insights, download the OPNsense report

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

I mainly rely on community support since the solution is open source.

Stephen Zoran

Senior Client Solutions Architect at a tech services company with 1,001-5,000 employees

If you say you do not have one, it is finished. This is where the monopoly starts.

Harry Fusser

Senior Solutions Engineer at a educational organization with 201-500 employees

Scalability Issues

Sentiment score

8.2

Fortinet FortiOS is highly scalable, adapting to different organizations, supporting growth and global deployments, yet may need hardware upgrades.

Sentiment score

6.8

OPNsense offers scalable and flexible network solutions, effectively supporting mid-sized to enterprise needs with appropriate hardware or virtualization.

When customers' networks grow and needs expand, we can easily switch between models to trade up devices.

Technology Consultant at NetWiser

It allows for the expansion of users and devices without additional licensing costs.

For more quotes and insights, download the Fortinet FortiOS report

Senior Manager at ITX360 (Pvt) Ltd

We have been using Fortinet for bandwidth shaping and many other bandwidth-related functions.

Mitul-Shah

Associate Director IT Operations at Procento

I use Zenarmor, pinning it to one core for packet inspection, and the CPU performance seems very good.

Stephen Zoran

Senior Client Solutions Architect at a tech services company with 1,001-5,000 employees

OPNsense's scalability is excellent; I just need to resize my hardware and upgrade the server, and voilà, I am good to go.

Mahmoud Suleiman

Senior IT Infrastructure Engineer at a real estate/law firm with 11-50 employees

In theory, OPNsense can handle small home networks and even large enterprise environments if deployed on sufficiently powerful hardware or virtualized on a clustered system.

For more quotes and insights, download the OPNsense report

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

Stability Issues

Sentiment score

7.8

Fortinet FortiOS is praised for stability, with minor issues usually tied to configurations or external factors, not the system.

Sentiment score

7.3

OPNsense is stable with occasional issues; praised for security and UI, performance varies with hardware and resource availability.

While the product is largely stable, it sometimes faces memory issues in specific versions like 11 OE, which can be disruptive.

Mitku Bitew

Director, IT Infrastructure Department at Zemen Bank S.C.

There were no lags, there were no issues, and no hanging of the firewall.

Mitul-Shah

Associate Director IT Operations at Procento

Stability is a seven out of ten because during version migrations, and sometimes with new versions, Fortinet is not as good.

For more quotes and insights, download the Fortinet FortiOS report

Technology Consultant at NetWiser

For home and small network use, OPNsense is also reliable, providing enterprise-grade security at no cost.

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

The only challenge faced was its inadequacy to manage large voice traffic effectively, even with dedicated hardware.

For more quotes and insights, download the OPNsense report

Senior Network Engineer at a comms service provider with 11-50 employees

At the latest code level, I haven't experienced any crashes.

Stephen Zoran

Senior Client Solutions Architect at a tech services company with 1,001-5,000 employees

Room For Improvement

Fortinet FortiOS requires improvements in VPN, pricing, compatibility, UI, security features, support, updates, deployment, and pricing consistency.

OPNsense users face VPN setup issues, inadequate documentation, performance shortfalls, high pricing, and request better usability and features.

Fortinet FortiOS faces memory issues, which can lead to unexpected downtimes.

Mitku Bitew

Director, IT Infrastructure Department at Zemen Bank S.C.

There should be more documentation on how to use the CLI or how to perform CLI versions of tasks that can be done through the GUI.

Network Administrator at a educational organization with 501-1,000 employees

Compared to other market leaders like Palo Alto and Check Point, FortiOS has many bugs in its initial releases.

For more quotes and insights, download the Fortinet FortiOS report

Senior Manager at ITX360 (Pvt) Ltd

Enhancing its performance for significant amounts of data traffic would make it closer to a perfect solution.

Senior Network Engineer at a comms service provider with 11-50 employees

It would be beneficial if they could create some videos on how to set it up themselves.

Administrator at a retailer with 10,001+ employees

The documentation should be clearer because I faced some difficulties navigating many options.

For more quotes and insights, download the OPNsense report

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

Setup Cost

Fortinet FortiOS is often pricey but justified by features, with agreements influencing costs, suitable for mid-size businesses.

OPNsense is a cost-effective, open-source solution for enterprises, reducing expenses compared to FortiGate and Palo Alto alternatives.

It is an affordable solution for us.

Technology Consultant at NetWiser

Fortinet products are somewhat pricey, similar to Cisco equivalents, however, they have justified their price point.

Network Administrator at a educational organization with 501-1,000 employees

I am satisfied with the pricing, licensing, and setup costs of FortiOS, rating it nine out of ten compared to other familiar leading firewalls.

For more quotes and insights, download the Fortinet FortiOS report

Senior Manager at ITX360 (Pvt) Ltd

I consider the pricing of OPNsense to be high when compared with other market products.

Senior Network Engineer at a comms service provider with 11-50 employees

OPNsense is free, the licensing and setup was easy.

For more quotes and insights, download the OPNsense report

Administrator at a retailer with 10,001+ employees

Valuable Features

Fortinet FortiOS is praised for UTM, user-friendly interface, robust security, excellent performance, cost-effectiveness, and seamless management.

OPNsense provides user-friendly configuration, robust security features, and adaptability, making it ideal for enterprise and IT network management.

It is user-friendly when it comes to turning on features, and it has been reliable and effective.

Network Administrator at a educational organization with 501-1,000 employees

The threat intelligence in FortiOS is very high, and the system is scalable without additional licensing costs.

Senior Manager at ITX360 (Pvt) Ltd

The solution offers good threat intelligence, which is crucial for our customers' security purposes.

For more quotes and insights, download the Fortinet FortiOS report

Technology Consultant at NetWiser

The most valuable features include the basic firewall functionality and the GeoIP location services.

Senior Network Engineer at a comms service provider with 11-50 employees

I can have a Wi-Fi VLAN and feel secure that the server network or the VM network that I have on a different VLAN are isolated, and they cannot talk to one another, which adds a great level of security.

Administrator at a retailer with 10,001+ employees

It offers enterprise-grade features such as intrusion detection and prevention system, VPN support, traffic shaping, and web filtering, all without license cost.

For more quotes and insights, download the OPNsense report

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

Categories and Ranking

Fortinet FortiOS

Ranking in Firewalls

19th

Average Rating

8.4

Reviews Sentiment

8.0

Number of Reviews

Ranking in other categories

No ranking in other categories

OPNsense

Ranking in Firewalls

7th

Average Rating

8.2

Reviews Sentiment

6.6

Number of Reviews

Ranking in other categories

No ranking in other categories

Mindshare comparison

As of August 2026, in the Firewalls category, the mindshare of Fortinet FortiOS is 1.1%, down from 1.1% compared to the previous year. The mindshare of OPNsense is 7.9%, down from 11.0% compared to the previous year. It is calculated based on PeerSpot user engagement data.

Firewalls Mindshare Distribution
Product	Mindshare (%)
OPNsense	7.9%
Fortinet FortiOS	1.1%
Other	91.0%

Firewalls

Featured Reviews

Mitul-Shah

Associate Director IT Operations at Procento

Single-pane management has simplified firewall control and has improved risk mitigation

I would not say that Fortinet FortiOS is not very scalable. Generally, what happens is that for enterprises, we hire consultants who do the capacity planning and sizing to determine what kind of firewalls to put in place. At the same time, it is not only the number of users; it also depends on the number of WAN links coming in and everything, because we have been using Fortinet for bandwidth shaping and many other bandwidth-related functions. They should improve their machine learning AI capabilities of Fortinet FortiOS because there is too much competition. Other players are also improving and making a lot of changes in their UI and overall operating system.

Read full review

Has helped simulate enterprise security setups and strengthens network segmentation practices

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

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.

Read full review

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Top Industries

By visitors reading reviews

Construction Company

12%

Comms Service Provider

Manufacturing Company

Financial Services Firm

Comms Service Provider

18%

Computer Software Company

Manufacturing Company

Outsourcing Company

Company Size

By reviewers

Large Enterprise

Midsize Enterprise

Small Business

By reviewers
Company Size	Count
Small Business	43
Midsize Enterprise	13
Large Enterprise	23

By reviewers
Company Size	Count
Small Business	32
Midsize Enterprise	6
Large Enterprise	8

Questions from the Community

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 kind of depends what you value most. PA is good at app control, web filtering a...

What is your experience regarding pricing and costs for Fortinet FortiOS?

I rate the pricing for FortiOS as eight or nine out of ten. It is an affordable solution for us.

What needs improvement with Fortinet FortiOS?

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 client, Open VPN and client, and PPTP client. Both also have intrusion detection a...

What is your experience regarding pricing and costs for OPNsense?

Setup cost is almost zero as one can simulate the whole environment using open source version. Pricing seems fair enough. Open source license allows a beginner to have a complete firewall solution ...

What needs improvement with OPNsense?

When I talk about VPN, I am not completely satisfied with the VPN functions of OPNsense. What I have received so far is that sometimes the VPN route caches for some time and sometimes I want to cha...

Fortinet FortiGate vs Fortinet FortiOS

Comparisons

Compared 12% of the time

Fortinet FortiWeb vs Fortinet FortiOS

Compared 7% of the time

Cisco Secure Firewall vs Fortinet FortiOS

Compared 6% of the time

Azure Firewall vs Fortinet FortiOS

Compared 6% of the time

Infoblox Advanced DNS Protection vs Fortinet FortiOS

Compared 2% of the time

More Fortinet FortiOS Competitors

Netgate pfSense vs OPNsense

Compared 49% of the time

Fortinet FortiGate vs OPNsense

Compared 6% of the time

IPFire vs OPNsense

Compared 6% of the time

Sophos Firewall vs OPNsense

Compared 5% of the time

Cisco Secure Firewall vs OPNsense

Compared 3% of the time

More OPNsense Competitors

Product Reports

Download Fortinet FortiOS product report

Fortinet FortiOS

August 2026

Download OPNsense product report

July 2026

Overview

Fortinet FortiOS is recognized for its intuitive interface, ease of use, and comprehensive security features, making it a valuable tool for network security and management. Its integration capabilities and affordability prove beneficial for small to mid-sized businesses.

Fortinet FortiOS stands out as a firewall operating system, offering solutions in network security with a user-friendly design. It provides strong management tools like Unified Threat Management, web filtering, intrusion prevention, and antivirus functionalities. Its scalability and robust support make it ideal for diverse business environments. Users can benefit from high availability, seamless integration with other networks, and SD-WAN capabilities. Though there is room for improvement in monitoring and logging features, as well as VPN complexity and browser compatibility, its comprehensive range of features supports secure operations.

What are some key features of Fortinet FortiOS?

Unified Threat Management: Consolidates multiple security features into one platform for streamlined protection.
Web Filtering: Blocks access to harmful websites to enhance browsing safety.
Intrusion Prevention: Identifies and mitigates network threats in real time.
Antivirus Capabilities: Detects and neutralizes malicious software before it infiltrates systems.
Advanced Threat Detection: Uses analytics to uncover sophisticated threats.

What benefits should users expect from Fortinet FortiOS?

Scalability: Easily adapts to an organization's growing security needs.
Stability: Provides consistent and reliable performance for network infrastructures.
Robust Support: Access to extensive resources and customer support for issue resolution.
Integration: Harmonizes efficiently with existing networks and third-party solutions.
Pricing: Offers a competitive and reasonable cost structure.

Fortinet FortiOS is leveraged across multiple industries for its strong security capabilities. Companies utilize it for secure connections, VPN setups, and traffic management. It is essential for organizations seeking to protect data centers, ensure secure branch connectivity, and deploy SD-WAN. Its design supports implementation in cloud environments and enhances virtual infrastructure protection, making it particularly suitable for small to mid-tier businesses looking for comprehensive security measures.

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.

Sample Customers

Black Gold Regional Schools, Amadeus Hospitality, Jefferson County, Chunghwa Telecom, City of Boroondara, Dimension Data

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.