PK3 File Format (.pk3)
A PK3 file is a Quake III Arena game archive, an ordinary ZIP file renamed with a .pk3 extension so id Tech 3's engine loads its maps, models, textures and sounds straight out of the package.
PK3 at a glance#
| Full name | Quake III game archive |
|---|---|
| File extension | .pk3 |
| Category | 3D Models |
| Developer | id Software |
| First released | 1999 |
| MIME types | application/zip |
| Compression | Lossless |
| FileFlip support | FileFlip reads this format but does not write it |
Strengths and limitations of PK3#
What PK3 does well
- Any ZIP tool opens it, since renaming the extension back to .zip is all it takes to see what's inside
- Bundles a mod or map's BSP levels, MD3 models, textures, sounds and scripts into the exact folder structure the engine expects
- The engine reads files straight out of the archive without needing them unpacked to disk first
Where PK3 falls short
- No standard packing order or compression level, so file size and load performance vary by how each individual pk3 was built
- Nothing inside is validated on the way in, so a broken or mismatched file inside the archive only fails once the engine tries to load it
- Specific to id Tech 3 and its direct derivatives; other engines with the same idea, like Doom 3's PK4, use a different extension
Use PK3 to package and distribute a Quake III Arena map or mod's assets as one file that the engine loads directly.
Convert a PK3 into its individual files when the goal is to reuse a specific model, texture or sound rather than run the package inside the game.
How to open a .pk3 file#
A .pk3 file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts PK3 into a format your machine already opens, and it does it in the browser tab rather than on a server.
| Platform | Programs that open it |
|---|---|
| Windows | 7-Zip, GtkRadiant, NetRadiant |
| macOS | The Unarchiver, ioquake3, OpenArena |
| Linux | ioquake3, OpenArena, GtkRadiant, NetRadiant |
| Web | FileFlip |
PK3 questions people ask#
What is a PK3 file?
A PK3 file is a Quake III Arena game archive, structurally just a ZIP file with the extension changed to .pk3 so id Tech 3's engine recognizes and loads it directly. It typically bundles a mod or map pack's BSP levels, MD3 models, textures and sounds together.
Can I open a PK3 file with a normal ZIP tool?
Yes. A PK3 file is an ordinary ZIP archive under a different extension, so any ZIP tool, or simply renaming the file to end in .zip, opens it and lists its contents.
Why does Quake III use PK3 instead of loose files?
Packing a mod or map's files into a single PK3 keeps them organized in the exact folder structure the engine expects and lets it read straight out of the archive without unpacking to disk first, which made distributing and installing custom content much simpler than shipping loose files.
Converting PK3 files#
Convert PK3 to another format
FileFlip does not write .pk3 files, so nothing on the site converts into this format. It works as a source only.
Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.