.WUX File Extension

WUX files are the compressed version of WUD files, which are typically created using Homebrew for Wii U to store game information dumped from a Wii U game. Since the game information is large in size (over 20 GB), multiple WUD files are created to store segments (around 2 GB) of the game. In order to reduce the size of a WUD file, the Wii U image compression tool can be used to compress the file and reduce it to a much smaller size, sometimes from sizes around 20 GB to 2-3 GB. The compression of the WUD file results in the WUX file.

You can decompress WUX files with the Wii U image compression tool, which results in a WUD file. You can also simply open a WUX file in Cemu by selecting File → Load and choosing the WUX file you want to open.