> ## Documentation Index
> Fetch the complete documentation index at: https://docs.buildpixel.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Engine versions

> Which UE versions are supported, and how the version is resolved per build.

## Supported

| Version      | Status              |
| ------------ | ------------------- |
| UE 5.4       | **Stable, default** |
| UE 5.3       | Stable              |
| UE 5.5       | Beta — coming soon  |
| UE 5.1 / 5.2 | Best-effort         |
| UE 4.x       | Not supported       |

## Resolution order

When a build runs, the engine version is resolved in this order:

1. **`ueVersion`** on the build setting (highest priority)
2. **`EngineAssociation`** from your `.uproject`
3. **Org default** (configured in Settings)

If the resolved version isn't supported, the build fails at validation.

## Switching versions

To upgrade a project:

1. Open the project in the new UE version locally, save, commit. The `.uproject` `EngineAssociation` updates automatically.
2. If any build setting has the old version pinned in `ueVersion`, update it.
3. Trigger a build. The first build after a version change rebuilds intermediates, so it's slower than usual. Subsequent builds are back to normal speed.

## Custom engine builds

If your team maintains a forked UE build with internal patches, that's an Enterprise scenario. Custom forks need engine-aware setup that managed BuildPixel doesn't do automatically. Talk to [enterprise@streampixel.io](mailto:enterprise@streampixel.io).

For minor toolchain customizations, use stock UE and pass any custom flags via your project's build configuration.