A good OPNsense box needs more than enough processing power: it needs the right network ports, dependable cooling, and hardware that fits your connection speed. The five mini PCs in this roundup range from compact fanless firewall appliances to a more powerful general-purpose system.
Before choosing, decide how many Ethernet interfaces you need and whether RAM and storage are included. Those details can matter more than a long processor specification.
Best 5 Mini PC for Opnsense Picks for 2026
Quiet Four-Port Gateway
VNOPN J3710 Fanless Firewall Mini PC
- Four Intel i226 LAN ports
- Fanless aluminum chassis
- 8GB RAM and 128GB mSATA SSD
Best For: Quiet four-port home firewall setups
High-Compute Dual-LAN Option
MINISFORUM NAB5R Core i5 Mini PC
- Core i5-13500H with 12 cores
- Dual 2.5GbE ports
- 16GB RAM and 512GB SSD
Best For: DIY dual-LAN builds needing extra compute
Six-Port Network Hub
EGSMTPC J6412 Fanless Firewall Mini PC
- Six Intel i226-V 2.5GbE ports
- Fanless aluminum chassis
- Expandable RAM and storage
Best For: Multi-WAN or segmented wired networks
Best for Expandable Memory
Sharevdi J4105 Fanless Firewall Mini PC
- Four Intel i226-V 2.5GbE ports
- 8GB RAM; stated 16GB maximum
- Fanless with 240GB mSATA SSD
Best For: Quiet four-port firewalls with a future RAM upgrade
Best for Flexible Storage
Glovary J3710 Four-Port Firewall Mini PC
- Four i225-V 2.5GbE ports
- mSATA, SATA 3.0, and Mini-PCIe slots
- Fanless; 8GB RAM maximum
Best For: Four-port builds needing a SATA storage connection
Quiet Four-Port Gateway – VNOPN J3710 Fanless Firewall Mini PC
If you want a mini pc for opnsense that can run quietly around the clock, this VNOPN appliance pairs a fanless aluminum chassis with four Intel i226 LAN ports. It comes with 8GB RAM and a 128GB mSATA SSD, and the seller lists OPNsense among its tested operating systems.
Best For: A quiet, four-port home firewall or network gateway.
Pros:
- Four Intel i226 LAN ports provide connections for WAN and segmented networks.
- Fanless design eliminates fan noise.
- Intel J3710 supports AES-NI, and RAM and storage are included.
Cons:
- Installed 8GB RAM is also the stated maximum.
- Storage uses mSATA; HDDs are not supported.
Its appeal is a ready-equipped, silent firewall platform with four ports. Choose it when that layout matters more than memory or drive expansion.
High-Compute Dual-LAN Option – MINISFORUM NAB5R Core i5 Mini PC
The MINISFORUM NAB5R is a mini pc for opnsense buyers who also want substantial general-purpose computing power, but it is not presented as an OPNsense-ready appliance. Its Core i5-13500H, 16GB RAM, 512GB SSD, and two 2.5GbE ports make it a candidate for a dual-interface firewall project if you are prepared to handle OS installation and compatibility checks.
Best For: Buyers who want a powerful dual-LAN mini PC and are comfortable setting up their own firewall OS.
Pros:
- 12-core, 16-thread Core i5-13500H provides ample processing headroom.
- Two 2.5GbE ports support a basic WAN/LAN layout.
- Includes 16GB DDR4 RAM and a 512GB PCIe SSD, with stated expansion options.
Cons:
- Ships with Windows 11 IoT Enterprise, not OPNsense.
- Two Ethernet ports offer less physical network separation than the four- and six-port appliances here.
- Fan cooling is less suited to buyers seeking a fanless box.
Buy this for its CPU and broader mini-PC flexibility, not for a turnkey firewall setup. Verify your intended OPNsense installation before making it a dedicated gateway.
Six-Port Network Hub – EGSMTPC J6412 Fanless Firewall Mini PC
For a mini pc for opnsense with room for multiple physical network connections, this EGSMTPC J6412 model offers six Intel i226-V 2.5GbE ports. Its fanless chassis, 8GB RAM, and 128GB SSD make it a practical starting point for a multi-WAN or segmented-network build, while the seller explicitly lists OPNsense compatibility.
Best For: Multi-WAN or VLAN-focused setups that benefit from six Ethernet ports.
Pros:
- Six 2.5GbE ports provide flexible physical connections.
- Fanless aluminum chassis keeps operation quiet.
- Two DDR4 SO-DIMM slots support up to 32GB RAM, with mSATA and SATA storage options.
- J6412 supports AES-NI for encryption workloads.
Cons:
- Ships with pfSense pre-installed rather than OPNsense, so switching systems requires setup.
- Firewall configuration is left to the user.
This is the strongest port-count choice of the three, especially if your network needs separate wired paths. Budget time to install your preferred OS and configure the firewall.
Best for Expandable Memory – Sharevdi J4105 Fanless Firewall Mini PC
If you want a mini pc for opnsense with four 2.5GbE ports and room to increase memory, this Sharevdi model is a practical starting point. Its Intel J4105 supports AES-NI, and the listed configuration includes 8GB DDR4 RAM and a 240GB mSATA SSD.
Best For: A quiet, four-port firewall build that may need more RAM later.
Pros:
- Four Intel i226-V 2.5GbE ports provide separate physical network connections.
- Fanless aluminum enclosure avoids fan noise.
- Included 8GB RAM can be upgraded to a stated maximum of 16GB.
Cons:
- Storage is limited to mSATA SSD; the listing says HDDs are not supported.
- J4105 is an older, low-power processor, so assess your intended workload before buying.
The stronger reason to choose this model is its combination of four i226-V ports, included storage, and a 16GB stated RAM ceiling—not its display outputs. Confirm the OS installation and configuration you need before deployment.
Best for Flexible Storage – Glovary J3710 Four-Port Firewall Mini PC
This Glovary mini pc for opnsense pairs a Pentium J3710 with four i225-V 2.5GbE ports in a fanless enclosure. The supplied configuration has 8GB RAM and a 128GB SSD, while its listed mSATA, SATA 3.0, and Mini-PCIe connections offer hardware flexibility.
Best For: A compact firewall setup where a SATA storage connection or Mini-PCIe slot matters more than additional RAM capacity.
Pros:
- Four i225-V 2.5GbE ports suit multi-interface network layouts.
- mSATA and SATA 3.0 connections are listed; a SATA cable is included.
- Fanless aluminum body measures a stated 11 × 10 × 3.5 cm.
Cons:
- The stated 8GB RAM maximum leaves no memory headroom beyond the included amount.
- Its older DDR3L memory platform may be less appealing if you prioritize newer components.
Choose this one for its port count and listed expansion connections. Although OPNsense compatibility is claimed, plan to handle installation and verify that the available memory fits your intended configuration.
How We Picked the Best Mini PC for Opnsense
We focused on the specifications that affect a small firewall build: Ethernet port count and speed, processor class, cooling design, and whether RAM and storage are included. Four selections are purpose-built firewall appliances with multiple onboard network ports. The MINISFORUM NAB5R offers substantially more general computing power, but its suitability as a router depends on how you plan to provide and connect network interfaces.
Specifications alone cannot establish real-world OPNsense throughput. VPN performance, intrusion detection, installed plugins, and network configuration can all change the result. Verify the seller’s exact configuration before ordering.
Quick Comparison
- For more physical network segments: The J6412 appliance lists six 2.5GbE ports, plus 8GB RAM and a 128GB SSD.
- For a four-port 2.5GbE firewall: The J4105 model lists four Intel i226-V ports; the equipped J3710 model lists four i225V ports, 8GB RAM, and a 128GB SSD.
- For a configurable compact appliance: The other J3710 listing specifies four Intel i226 ports, but its title does not confirm included RAM or storage.
- For broader home-lab use: The Core i5-13500H NAB5R lists 16GB RAM and a 512GB SSD, though its listing does not establish a comparable set of dedicated firewall ports.
Key Buying Factors for a Mini PC for Opnsense
Ethernet Ports and Network Layout
Count the interfaces you actually need: WAN, LAN, and any separately connected networks. VLANs can divide traffic over fewer ports if your switches support them, while extra physical ports make some layouts simpler. A 2.5GbE port does not by itself guarantee 2.5Gbps routing with every feature enabled; your modem, switches, cables, and workload also matter.
Processor, Memory, and Storage
A basic firewall generally needs less compute than a build running VPN services, traffic inspection, or other demanding packages. Choose for your planned features rather than core count alone. Check memory and SSD inclusion carefully: an appliance sold without them may cost more to complete than an equipped alternative.
Cooling, Compatibility, and Setup
Fanless units avoid fan noise, making them appealing near a desk or living space, but still need airflow around the case. Confirm the exact Ethernet controller and OPNsense support for the version you intend to install, particularly if a listing has multiple hardware revisions. Plan for a display and keyboard during installation unless you have another supported setup method.
Who Should Buy Which Mini PC for Opnsense?
Choose the six-port J6412 if you want the most onboard interfaces among these listings. Pick an equipped four-port J3710 if you want RAM and storage specified upfront, or compare the J4105 and i226-based J3710 if port-controller details are central to your build. Consider the NAB5R for a more versatile mini PC or lab host—not as a direct substitute for a multi-port appliance without first confirming your network-interface plan. The best Mini PC for Opnsense is the one whose complete, verified configuration matches your network, not simply the one with the fastest CPU.