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Cybersecurity · head to head

Authelia vs GNAT Pro

Authelia logo

Authelia

Cybersecurity

Open-source authentication and two-factor portal for reverse proxies

From
Free
Free plan
Yes
Full reviewWebsite
GNAT Pro logo

GNAT Pro

Developer Tools

Software development environments and toolchains for Ada, C/C++ and Rust

From
On request
Free plan
No
Full reviewWebsite

The short version

  • Only Authelia has a free tier, so it costs nothing to try first.
  • Each has a real cost: Authelia depends on a reverse proxy: it is not a standalone identity provider; GNAT Pro no pricing published on website; requires contacting AdaCore directly for quotes
  • Prices and features above were last checked on 29 August 2026.

Where they differ

Only the attributes on which Authelia and GNAT Pro actually diverge.

Attributes where Authelia and GNAT Pro differ
AttributeAutheliaGNAT Pro
Starting priceFreeOn request
Pricing modelOpen source, no licence feequote
Free tierYesNo
PlatformsDocker, Kubernetes, Linux, Self-hostedWeb
CategoryCybersecurityDeveloper Tools

Identical on both: user rating (Not yet rated).

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 Authelia

  • Reverse proxy integration
  • Two-factor authentication
  • Access control rules
  • Lightweight backends

Only in GNAT Pro

Nothing recorded that Authelia does not also cover.

What people use each for

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

Authelia

  • Putting a login and 2FA in front of self-hosted services that have nonenot GNAT Pro
  • Adding SSO across a small set of internal tools without a full identity platformnot GNAT Pro
  • Home and small-team infrastructure behind a single reverse proxynot GNAT Pro

GNAT Pro

  • Building certified avionics software meeting DO-178B/C standardsnot Authelia
  • Developing automotive embedded systems with ISO-26262 compliancenot Authelia
  • Integrating Ada, C/C++, and Rust components in single codebasenot Authelia
  • Managing software supply chain vulnerabilities and SBOMsnot Authelia
  • Supporting long-lived software systems spanning decadesnot Authelia

Where each one falls short

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

Authelia

  • Depends on a reverse proxy: it is not a standalone identity provider
  • Configuration is YAML-first with no administrative interface, so changes mean editing files
  • Not a full IAM: user management, provisioning and federation are limited compared with Keycloak
  • Scales poorly as an organisation-wide identity solution, which is not its target

GNAT Pro

  • No pricing published on website; requires contacting AdaCore directly for quotes
  • Vendor indicates per-user, per-year subscription model but does not disclose specific costs

Pricing, plan by plan

Authelia

Free
  • AutheliaFree
    • Full functionality
    • No usage limits
    • Community support

GNAT Pro

On request

No published plan breakdown. See the GNAT Pro review.

Which should you pick?

Choose Authelia if

  • You need reverse proxy integration.
  • You want to start without paying.
  • You work on Docker, Kubernetes, Linux, Self-hosted.
  • You also want two-factor authentication.
Authelia review

Choose GNAT Pro if

Nothing in the data separates GNAT Pro from Authelia on the points above - pick on price and on how each one feels to use.

GNAT Pro review

Questions people ask

Is Authelia or GNAT Pro better?
Neither clearly leads. Authelia starts at Free and GNAT Pro at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Authelia or GNAT Pro?
Authelia has a free tier; the other does not. Paid plans start at Free for Authelia and On request for GNAT Pro.
Does Authelia or GNAT Pro run on more platforms?
Authelia runs on Docker, Kubernetes, Linux, Self-hosted. GNAT Pro runs on Web.
Can I use Authelia for free?
Yes. Authelia has a free tier, so you can try it without paying. GNAT Pro starts at On request.
What is Authelia best used for?
Authelia is most often used for putting a login and 2fa in front of self-hosted services that have none, adding sso across a small set of internal tools without a full identity platform, home and small-team infrastructure behind a single reverse proxy. Of those, putting a login and 2fa in front of self-hosted services that have none and adding sso across a small set of internal tools without a full identity platform are not what GNAT Pro is typically brought in for.
What can Authelia do that GNAT Pro cannot?
Authelia covers Reverse proxy integration, Two-factor authentication, Access control rules, Lightweight backends.

Answered from the vendors’ own pages

Authelia: Is Authelia free?

Yes, open source with no licence fee.

GNAT Pro: How much does GNAT Pro cost?

GNAT Pro pricing is not published on the website. Customers must request a pricing quote by contacting AdaCore directly or speaking with a GNAT Pro expert.

Source
Authelia: Does Authelia need a reverse proxy?

Yes. It integrates through forward authentication with Nginx, Traefik, Caddy or HAProxy rather than sitting in front of traffic itself.

GNAT Pro: What is GNAT Pro licensing model?

GNAT Pro is sold on a per-user, per-year basis with no license locks. Customers can request pricing for their specific needs.

Source
Authelia: Authelia or Keycloak?

Authelia is far lighter and aimed at protecting self-hosted services behind a proxy. Keycloak is a full identity and access management platform, and much more to run.

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