Skip to main content

IO Store Support

Repak X fully supports Unreal Engine's IO Store format alongside Legacy PAK files.

What is IO Store?

IO Store (.utoc / .ucas) is Unreal Engine's modern asset packaging format, offering better performance and loading times compared to Legacy PAK files.

Legacy PAK vs IO Store

FeatureLegacy PAKIO Store
Format.pak.utoc / .ucas
CompressionOptionalOodle (recommended)
PerformanceStandardOptimized

Oodle Compression

IO Store bundles can be compressed with Oodle compression to reduce file size while maintaining fast load times.