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Cybersecurity · head to head

Authelia vs FireMonkey

Authelia logo

Authelia

Cybersecurity

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

From
Free
Rated
-
Full reviewWebsite
FireMonkey logo

FireMonkey

Browser Extensions

User scripts and user styles in one Firefox extension

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Authelia depends on a reverse proxy: it is not a standalone identity provider; FireMonkey firefox only, and requires a recent one: version 93 on desktop, 113 on Android.
  • They diverge on capability: Authelia covers Reverse proxy integration, FireMonkey covers Scripts and styles together.
  • Prices and features above were last checked on 15 September 2026.

Where they differ

Only the attributes on which Authelia and FireMonkey actually diverge.

Attributes where Authelia and FireMonkey differ
AttributeAutheliaFireMonkey
Pricing modelOpen source, no licence feeopen-source
PlatformsDocker, Kubernetes, Linux, Self-hostedFirefox
CategoryCybersecurityBrowser Extensions

Identical on both: starting price (Free), free tier (Yes), 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 FireMonkey

  • Scripts and styles together
  • Monaco editor with ESLint
  • Unlimited client-side storage
  • Global injection
  • Notifications and clipboard
  • Firefox for Android

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 FireMonkey
  • Adding SSO across a small set of internal tools without a full identity platformnot FireMonkey
  • Home and small-team infrastructure behind a single reverse proxynot FireMonkey

FireMonkey

  • Running user scripts and user styles without two separate extensionsnot Authelia
  • Restyling sites with CSS alongside scripted behaviour changesnot Authelia
  • Editing scripts in a full editor inside the browsernot Authelia
  • Injecting CSS globally across every sitenot Authelia
  • Managing a mixed library of scripts and styles from one dashboardnot 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

FireMonkey

  • Firefox only, and requires a recent one: version 93 on desktop, 113 on Android.
  • Not a drop-in replacement for Greasemonkey, Tampermonkey or Stylus. The project says so itself, so an existing library may need adjusting.
  • A much smaller user base than Tampermonkey or Violentmonkey, which means fewer people have hit the bug you are about to hit.
  • No Chrome, Edge or Safari build, so it cannot be the answer for anyone working across browsers.
  • Combining scripts and styles in one extension also combines the blast radius: one extension with permission to inject both into every page.

Pricing, plan by plan

Authelia

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

FireMonkey

Free
  • Open sourceFree
    • MPL-2.0 licensed
    • Unlimited scripts and styles
    • No account required

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 FireMonkey if

  • You need scripts and styles together.
  • You want to start without paying.
  • You work on Firefox.
  • You also want monaco editor with eslint.
FireMonkey review

Questions people ask

Is Authelia or FireMonkey better?
Neither clearly leads. Authelia starts at Free and FireMonkey at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Authelia or FireMonkey?
Authelia starts at Free and FireMonkey at Free.
Does Authelia or FireMonkey run on more platforms?
Authelia runs on Docker, Kubernetes, Linux, Self-hosted. FireMonkey runs on Firefox.
Can I use Authelia for free?
Both have a free tier, so you can try either at no cost before committing.
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 FireMonkey is typically brought in for.
What can Authelia do that FireMonkey cannot?
Authelia covers Reverse proxy integration, Two-factor authentication, Access control rules, Lightweight backends. FireMonkey covers Scripts and styles together, Monaco editor with ESLint, Unlimited client-side storage, Global injection.

Answered from the vendors’ own pages

Authelia: Is Authelia free?

Yes, open source with no licence fee.

FireMonkey: What makes FireMonkey different from Violentmonkey?

It manages user styles as well as user scripts. The usual arrangement is a script manager plus a separate style manager such as Stylus; FireMonkey replaces both with one extension.

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.

FireMonkey: Which browsers does FireMonkey support?

Firefox only. Desktop requires Firefox 93 or later and Android requires 113, with an API minimum of 102.

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.

FireMonkey: Is FireMonkey open source?

Yes, under the MPL-2.0 licence.

Source
FireMonkey: Will my existing Tampermonkey scripts work?

Not necessarily. The project states that while it shares functionality with Greasemonkey, Tampermonkey and Stylus, there are differences, so scripts and styles written for those may need adjusting.

Source
FireMonkey: What editor does FireMonkey use?

Current versions use the Monaco editor with ESLint, the same editor component that powers VS Code.

Source
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