A WUD file contains a disk image dumped from a Wii U game disc. WUD files store information about Wii U games. Emulators like Cemu can run WUD files on computers. The large size of Wii U game data requires splitting WUD files into segments, usually around 2 GB each. A user dumps game data from a Wii U console into WUD files using Homebrew software.
You can compress WUD files to save disk space using the Wii U compression tool. This converts WUD files into .WUX files. Common WUD filenames indicate file order: game_part1.wud contains the first dumped segment of a Wii U game.
Windows can’t open .wud files by default. You need software associated with the .wud extension to open these files. Cemu and other Wii U emulators can open merged segmented WUD files to emulate Wii U games on a computer.
Cemu