The .x file extension was introduced with DirectX 2.0 to contain files of the X file format; and DirectX 6.0 introduced methods that enable reading from and writing to .x files.[1]

X file format
Filename extension
Developed byMicrosoft
Type of format3D model format
Extended todotXSI

It is a simple file containing geometry meshes and material information that can be viewed in the DirectX Viewer, a program available with the 2008 DirectX June SDK (Software Development Kit). Because the SDK provided the means to load and save assets in this format, it was often used as a simple way of getting assets into and out of game programs. As of 2014, the file format has been deprecated for a long time [2] and the interchange role is better served by a more modern format like Autodesk FBX.

See alsoEdit

  • dotXSI - an extended format of X file format


  1. ^ Microsoft - X Files (Legacy) (Direct3D 9)
  2. ^ Chuck Walbourn. "DirectX Mesh". Games for Windows and the DirectX SDK. Retrieved April 21, 2015.