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Flax Engine vs Unreal Engine

Flax Engine logo

Flax Engine

Game Development

Modern 3D game engine with visual editor

From
Free
Rated
-
Full reviewWebsite
Unreal Engine logo

Unreal Engine

Entertainment

The world's most open and advanced real-time 3D creation tool

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Flax Engine flax charges a 4% royalty on game earnings above $250,000, assessed per calendar quarter; Unreal Engine 5% royalty triggered on any project exceeding $1 million in gross revenue across all revenue sources
  • They diverge on capability: Flax Engine covers 3D graphics rendering, Unreal Engine covers Real-time ray tracing.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Flax Engine and Unreal Engine actually diverge.

Attributes where Flax Engine and Unreal Engine differ
AttributeFlax EngineUnreal Engine
Pricing modelfreeUnknown
PlatformsWindows, Linux, Playstation, XboxPC, macOS, Linux, PlayStation, Xbox, Nintendo Switch, iOS, Android, VR, AR
CategoryGame DevelopmentEntertainment
Founded20171991

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 Flax Engine

  • 3D graphics rendering
  • Visual editor
  • C# scripting
  • Physics engine
  • Audio system
  • Particle effects
  • Skeletal animation
  • Material system

Only in Unreal Engine

  • Real-time ray tracing
  • Nanite geometry
  • Lumen global illumination
  • Blueprint visual scripting
  • C++ programming
  • World composition
  • Animation systems
  • Audio engine

Both cover

  • Visual Studio
  • Local deployment
  • Windows support

What people use each for

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

Flax Engine

  • Building 3D games in C# and C++ with full engine source accessnot Unreal Engine
  • Multi-platform deployment from one editornot Unreal Engine
  • Prototyping with the bundled Flax Samples projectsnot Unreal Engine

Unreal Engine

  • AAA game developmentnot Flax Engine
  • Indie game creationnot Flax Engine
  • Architectural visualizationnot Flax Engine
  • Film and TV productionnot Flax Engine
  • VR/AR experiencesnot Flax Engine

Where each one falls short

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

Flax Engine

  • Flax charges a 4% royalty on game earnings above $250,000, assessed per calendar quarter
  • Free use is granted for non-commercial or educational usage; commercial releases fall under the royalty
  • Users must accept the Flax Engine End-User License Agreement before using the engine or its tools, so it is not an OSI open source licence despite the source being on GitHub
  • Non-game uses such as in-house tools or SaaS products need a custom licence negotiated with the vendor, and no rate card is published for per-seat or flat-fee options

Unreal Engine

  • 5% royalty triggered on any project exceeding $1 million in gross revenue across all revenue sources
  • Smaller mobile game ecosystem compared to Unity, with fewer optimized mobile libraries and live-ops services

Pricing, plan by plan

Flax Engine

Free
  • FreeFree
    • Full engine
    • Visual editor
    • C# scripting

Unreal Engine

Free
  • Game DevelopmentFree
    • Nanite geometry
    • Lumen global illumination
    • Blueprint visual scripting
  • Non-Game Commercial$1850/year
    • No royalties
    • Enterprise features

Which should you pick?

Choose Flax Engine if

  • You need 3d graphics rendering.
  • You want to start without paying.
  • You work on Windows, Linux, Playstation, Xbox.
  • You also want visual editor.
Flax Engine review

Choose Unreal Engine if

  • You need real-time ray tracing.
  • You want to start without paying.
  • You work on PC, macOS, Linux, PlayStation, Xbox, Nintendo Switch, iOS, Android, VR, AR.
  • You also want nanite geometry.
Unreal Engine review

Questions people ask

Is Flax Engine or Unreal Engine better?
Neither clearly leads. Flax Engine starts at Free and Unreal Engine at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Flax Engine or Unreal Engine?
Flax Engine starts at Free and Unreal Engine at Free.
Does Flax Engine or Unreal Engine run on more platforms?
Flax Engine runs on Windows, Linux, Playstation, Xbox. Unreal Engine runs on PC, macOS, Linux, PlayStation, Xbox, Nintendo Switch, iOS, Android, VR, AR.
Can I use Flax Engine for free?
Both have a free tier, so you can try either at no cost before committing.
What is Flax Engine best used for?
Flax Engine is most often used for building 3d games in c# and c++ with full engine source access, multi-platform deployment from one editor, prototyping with the bundled flax samples projects. Of those, building 3d games in c# and c++ with full engine source access and multi-platform deployment from one editor are not what Unreal Engine is typically brought in for.
What can Flax Engine do that Unreal Engine cannot?
Flax Engine covers 3D graphics rendering, Visual editor, C# scripting, Physics engine. Unreal Engine covers Real-time ray tracing, Nanite geometry, Lumen global illumination, Blueprint visual scripting. Both handle Visual Studio, Local deployment, Windows support.

Answered from the vendors’ own pages

Flax Engine: How much does Flax Engine cost?

Flax Engine is free during development. Once you ship a game commercially, you pay a 4% royalty on earnings only if your quarterly revenue exceeds $250,000 in a calendar quarter. Below that threshold, there is no royalty charge.

Source
Unreal Engine: What is Unreal Engine's royalty structure?

Unreal Engine is free upfront with a 5% royalty on gross revenue worldwide after a project exceeds $1 million in lifetime gross revenue. This includes in-app purchases, advertising, and direct sales but excludes indirect revenue.

Source
Flax Engine: Is Flax Engine free for educational and uncommercial projects?

Yes. Flax Engine is free for uncommercial or educational usage. You only pay royalties when you release a commercial product that exceeds the $250,000 quarterly earnings threshold.

Source
Unreal Engine: What platforms can Unreal Engine target?

Unreal Engine supports PC, VR, AR, gaming consoles, and mobile devices. The royalty fee applies across all platforms.

Source
Flax Engine: Do all Flax Engine users get access to the same features?

Yes. There is one version of Flax Engine. All users get full engine access with all features, supported platforms, complete editor source code on GitHub, sample projects, and free deployment to all supported platforms.

Source
Unreal Engine: What are Unreal Engine's graphics capabilities?

Unreal Engine 5 features Nanite virtualized geometry and Lumen global illumination, enabling photorealistic AAA workflows. Nanite replaces traditional LOD systems with 128-triangle clusters and software rasterization for superior visual fidelity.

Source
Flax Engine: Does Flax Engine offer custom licensing options?

Yes. For non-game industries or specific needs, Flax Engine offers custom licensing including per-seat licensing (monthly or yearly) or flat fees per project, with pricing based on team size and product use case.

Source
Unreal Engine: Do non-game developers pay royalties?

No. Non-game commercial teams pay $1,850 per seat per year instead of royalties. This covers enterprise use cases outside traditional game development.

Source
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