Overview

Facter is a command-line system-information collector designed to feed infrastructure management, especially Puppet. It is best suited to administrators who need machine facts in automation rather than a quick, graphical readout.

Key features

Facter gathers hardware, network, and operating-system details. Its built-in core facts include legacy and structured forms, although the facts available depend on the system being queried. Legacy facts do not appear in normal CLI output; use --show-legacy when older fields are needed. That default keeps routine output focused, but users relying on legacy fields must remember the extra option.

For tailored collection, custom facts can be written in Ruby, and multiple resolutions can determine a fact's value. External facts provide another route, returning static data or results from an executable script or program. This flexibility serves teams adapting collection to their infrastructure, while the Ruby examples make custom extensions a better fit for people comfortable with Ruby than for users seeking a turnkey utility.

Facts may be structured as hashes or arrays, and Puppet retains Boolean, numeric, and structured values rather than converting them to strings. Administrators can block fact groups or set time-to-live caching, useful when collection is slow. The configuration work is a real cost: Facter does not create facter.conf, so users must create it themselves or manage it with a module.

Puppet collects system information with Facter before requesting a catalog or compiling one with puppet apply; facts are also accessible in manifests. Puppet-specific facts can be loaded from the CLI with --puppet. PuppetDB's API can support tools for searching and reporting on infrastructure facts. On Windows, Facter 4.21 added disk and partition facts retrieved through Windows Management Instrumentation.

Pricing

Facter is free. The Puppet Core Developer plan costs 0.00 USD per free and covers fewer than 25 nodes, making it the clear fit for smaller deployments that need the core offering. For 25 or more nodes, Puppet Core Commercial uses custom pricing. Puppet Enterprise and Puppet Enterprise Advanced also use custom pricing and require contacting sales. Those are Puppet plan tiers, not a reason to assume the Facter command-line tool itself has a paid license.

Platforms

Facter supports Linux, macOS, Windows, and self-hosted environments. Its command-line interface suits scripted or managed workflows; it is not positioned as a graphical system-information viewer.

Who it's for

Choose Facter when system facts need to become inputs to Puppet workflows, or when infrastructure teams need custom and external facts, structured values, or collection controls. It is less suitable for someone who only wants a one-off hardware summary and does not want to configure a command-line tool. Custom Ruby facts also favor teams able to maintain Ruby code.

Pros and cons

Pros

Built for Puppet workflows: facts can inform catalog requests, puppet apply, and manifests.
Flexible collection: Ruby custom facts, external scripts, and multiple resolutions accommodate infrastructure-specific needs.
Useful controls and data fidelity: group blocking and TTL caching tune collection, while Puppet preserves structured, Boolean, and numeric values.
Free core plan: the Puppet Core Developer tier covers fewer than 25 nodes at no charge.

Cons

Manual configuration: users must create facter.conf or manage it with a module.
Ruby is a hurdle for custom facts: extending collection is less convenient without Ruby familiarity.
Legacy output requires an option: older facts are hidden by default and need --show-legacy.
Core Developer has a node cap: deployments with 25 or more nodes move to custom-priced Core Commercial.

Alternatives

System Information Software is the broader category to browse when comparing tools beyond Facter's infrastructure-focused approach.

Choose Fastfetch for a free, MIT-licensed command-line tool with 75+ system-information modules and support for Android, Linux, macOS, and Windows. ASTRA32 is a Windows-only option with a free tier for non-commercial use. For Linux and self-hosted environments, hw-probe is free and centers on anonymous hardware-detail collection to help people collaboratively debug hardware problems.

HWMonitor is worth considering for Windows PC hardware-sensor monitoring, or Android support; its free Windows edition covers x86/x64, while HWMonitor PRO Standard is 19.95 USD per once. Windows users can also compare SIW, which offers a free Viewer and a free 14-day trial version. For macOS, EtreCheckPro has a free download with unlimited use, basic reports and diagnostics, and command-line use; its Power User package costs 19.99 USD per once. Linux users wanting a free, GNU/Linux-focused Perl utility can consider inxi. WinAudit is another free Windows option, with no setup.

Verdict

Facter is the right choice for administrators who need configurable system facts inside Puppet workflows, particularly when structured data and collection controls matter. Its strongest reason to choose is that close fit with Puppet; its clearest reason to look elsewhere is the manual configuration and command-line overhead for straightforward, standalone system checks.

	Facter	SIW
Free plan	Yes	Yes
Free trial	No	Yes
Paid from	Free	$3.33/mo
Open source	No	No
Platforms	Linux, macOS, self-hosted, Windows	Windows
Free plan	Yes	No
Command-line interface	Yes	Yes
Operating systems	—	windows
Firmware details	—	Yes
Installed software	—	Yes
Portable version	—	Yes
Report export	—	html

Facter vs SIW

Facter

SIW