File with a .KFX extension contains a bitmap and information on that bitmap, stored in the Kofax Group 4 format. Within the file, there is a 128 byte header with size, colour depth and resolution of the image along with the time when it was created and modified previously. KFX files may also contain a textbox with a description.

Images in the KFX format are created and edited with the Kofax software. The programs storing KFX files are used for imaging, processing and scanning.