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Networking · head to head

pfSense vs Prometheus

pfSense logo

pfSense

Networking

Open source firewall software with a free Community Edition and a separate commercial Plus edition sold by Netgate

From
Free
Rated
-
Full reviewWebsite
Prometheus logo

Prometheus

Networking

Open source monitoring and alerting toolkit for cloud native environments

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: pfSense pfSense CE and pfSense Plus are not simply the same software with a support contract layered on top; Plus is a separately developed edition with its own feature set, and moving between them is a migration, not a toggle; Prometheus not suitable for per-request billing as collected data lacks 100% accuracy
  • They diverge on capability: pfSense covers Stateful firewall and NAT, Prometheus covers Multi-dimensional Data Model.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which pfSense and Prometheus actually diverge.

Attributes where pfSense and Prometheus differ
AttributepfSensePrometheus
Pricing modelOpen source Community Edition, free; commercial Plus edition sold separately by Netgateopen-source
PlatformsLinuxLinux, macOS, Windows
FoundedUnknown2015

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Networking).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in pfSense

  • Stateful firewall and NAT
  • VPN support
  • Traffic shaping and QoS
  • Package ecosystem
  • CE and Plus editions

Only in Prometheus

  • Multi-dimensional Data Model
  • PromQL Query Language
  • Pull-based Collection
  • Service Discovery
  • Alerting Rules
  • Federation
  • Local Storage
  • Grafana

What people use each for

The jobs each tool is most often brought in to do.

pfSense

  • A home user or small business wanting a free, fully-featured firewall on commodity hardware with no licence costnot Prometheus
  • A business wanting an integrated firewall appliance with vendor support, typically buying a Netgate appliance bundled with pfSense Plusnot Prometheus
  • A team wanting to evaluate advanced features like real-time threat intelligence before committing to Netgate hardware or a Plus migrationnot Prometheus
  • An organisation replacing an expensive commercial firewall with an open source alternative while retaining the option to add commercial support laternot Prometheus

Prometheus

  • Monitoring and alerting systemnot pfSense
  • Time-series databasenot pfSense
  • Infrastructure metrics collectionnot pfSense

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

pfSense

  • pfSense CE and pfSense Plus are not simply the same software with a support contract layered on top; Plus is a separately developed edition with its own feature set, and moving between them is a migration, not a toggle
  • Running Plus on non-Netgate hardware depends on Netgate's current migration terms, which have changed over time, so a buyer planning to use white-box hardware with Plus should verify current eligibility rather than assume it works as it did previously
  • CE has no official vendor support channel; a business relying on it for production firewalling without a support contract is self-supporting on community forums
  • Some newer features and threat intelligence integrations are Plus-only, so CE users do not get feature parity going forward even though both editions remain under active development
  • Netgate's own appliance pricing and the terms of the CE-to-Plus migration path are not always clearly presented in one place, requiring some digging to understand the real total cost of a Plus deployment on non-Netgate hardware
  • As with any self-managed firewall, security depends on the operator applying updates and correctly configuring rules; there is no managed security operations layer included even in Plus

Prometheus

  • Not suitable for per-request billing as collected data lacks 100% accuracy
  • Hard limit on scrape body size; large responses cause scrape failure
  • Per-scrape sample limit enforced; exceeding limit marks targets as failed
  • Not designed for long-term durable storage; optimised for metrics collection

Pricing, plan by plan

pfSense

Free
  • pfSense CEFree
    • Full firewall and routing functionality
    • No vendor lock-in to hardware
    • Community support
  • pfSense Plus (via Netgate appliance)$undefined/one-time
    • Bundled with Netgate hardware appliances from around $189
    • Threat intelligence feeds
    • Certified support tiers

Prometheus

Free
  • Prometheus (Open Source)Free
    • 100% open source
    • Community-driven project
    • Apache 2 License

Which should you pick?

Choose pfSense if

  • You need stateful firewall and nat.
  • You want to start without paying.
  • You work on Linux.
  • You also want vpn support.
pfSense review

Choose Prometheus if

  • You need multi-dimensional data model.
  • You want to start without paying.
  • You work on Linux, macOS, Windows.
  • You also want promql query language.
Prometheus review

Questions people ask

Is pfSense or Prometheus better?
Neither clearly leads. pfSense starts at Free and Prometheus at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, pfSense or Prometheus?
pfSense starts at Free and Prometheus at Free.
Does pfSense or Prometheus run on more platforms?
pfSense runs on Linux. Prometheus runs on Linux, macOS, Windows.
Can I use pfSense for free?
Both have a free tier, so you can try either at no cost before committing.
What is pfSense best used for?
pfSense is most often used for a home user or small business wanting a free, fully-featured firewall on commodity hardware with no licence cost, a business wanting an integrated firewall appliance with vendor support, typically buying a netgate appliance bundled with pfsense plus, a team wanting to evaluate advanced features like real-time threat intelligence before committing to netgate hardware or a plus migration, an organisation replacing an expensive commercial firewall with an open source alternative while retaining the option to add commercial support later. Of those, a home user or small business wanting a free, fully-featured firewall on commodity hardware with no licence cost and a business wanting an integrated firewall appliance with vendor support, typically buying a netgate appliance bundled with pfsense plus are not what Prometheus is typically brought in for.
What can pfSense do that Prometheus cannot?
pfSense covers Stateful firewall and NAT, VPN support, Traffic shaping and QoS, Package ecosystem. Prometheus covers Multi-dimensional Data Model, PromQL Query Language, Pull-based Collection, Service Discovery.

Answered from the vendors’ own pages

pfSense: What is the difference between pfSense CE and pfSense Plus?

CE is the free, open source edition installable on any compatible hardware; Plus is a commercial edition from Netgate with additional features and support, typically bundled with Netgate appliances.

Prometheus: What does Prometheus cost?

Prometheus is completely free and open source. There are no pricing tiers or paid plans. The entire project is licensed under Apache 2 and hosted on GitHub.

Source
pfSense: Can I run pfSense Plus on my own hardware?

It is possible through a migration from a CE installation via Netgate's official channel, but the terms and availability of that path have changed over time and should be confirmed directly with Netgate.

Prometheus: Is Prometheus commercial software or free?

Prometheus is 100% open source and community-driven. It is a CNCF graduated project with no commercial restrictions or licensing fees.

Source
pfSense: Is pfSense CE really free with no catch?

Yes, CE has no licence fee and no hardware lock-in, though it comes with community rather than vendor support.

Prometheus: How is Prometheus licensed?

Prometheus is licensed under the Apache 2 License, which permits free use, modification, and distribution for commercial and non-commercial purposes.

Source
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