.PK3 File Extension

Compressed game data file used by games based on the Quake III engine (id Tech 3), which was developed by id Software; may contain maps, textures, audio clips, or other data used for gameplay; can be modified to create custom game content.

PK3 files are similar to .PAK game data files, but are based on a newer format. Since PK3 files are compressed using Zip compression, they can be renamed with a .ZIP file extension and extracted using a file decompression program such as Corel WinZip or PKWARE PKZIP.

Quake III PK3 files should be saved in one of the following directories: quake3/​q3ut3, quake3/​baseq3, or quake3arena/​q3ut3.

NOTE: Examples of games that were developed using the id Tech 3 engine include Quake III Arena, Star Wars Jedi Knight II: Jedi Outcast, Soldier of Fortune II: Double Helix, Return to Castle Wolfenstein, and Call of Duty Classic.

A PK3 file may also be a game data package used by ZDoom and Sonic Robo Blast 2 (SRB2) as an alternative to the .WAD format to package game data. It is a Zip-compressed package that typically contains graphics, sounds, maps, and other game data.

PK3 files are primarily used by ZDoom, an application used for running older games such as Doom, Heretic, and Hexen. However, they may also be used by Sonic Robo Blast 2 (SRB2), a fan-made, open-source Sonic the Hedgehog game.

SRB2 began using PK3 files in version 2.2, replacing .SRB files to store game resources. SRB2 also utilizes PK3 files to store game add-ons, along with Doom WAD files.

Various games, such as ZDoom, GZDoom, and Sonic Robo Blast 2 support PK3 files.

If you are a game modder looking to edit the content in the PK3 file, you can use SLADE, a free utility for Windows, macOS, and Linux.

Since PK3 files are Zip-compressed, you can unpackage and access the resources in the files with Zip utility, such as Microsoft File Explorer (Windows), Corel WinZip (Windows), Apple Archive Utility (macOS), and PeaZip (multiplatform).