.PK4 File Extension
File TypeDoom 3 Engine Game Data File
What is a PK4 file?
Compressed game data file used by games that use the id Tech 4 game engine, which was developed by id Software for Doom 3; stores game assets, such as maps, graphics, audio files, or other data used for gameplay; similar to the .PK3 format.
Since PK4 files are compressed using Zip compression, they can be decompressed using any compatible Zip decompression utility.
Other games that use the id Tech 4 engine include Quake 4, Prey, Wolfenstein, and Brink.