DFI File

What are DFI files and how to open them

Are you having problems opening a DFI file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your DFI files.

What is a DFI file?

DFI files have multiple uses, and Digifont Outline Font Description is one of them. Read more about the other uses further down the page.

Digifont Outline Font Description

We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

How to open DFI files

Important: Different programs may use files with the DFI file extension for different purposes, so unless you are sure which format your DFI file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested two different DFI openers which you will find listed below.

Last updated: October 27, 2026

All known file formats using extension .DFI

While Digifont Outline Font Description is a popular type of DFI-file, we know of 4 different uses of the .DFI file extension. Different software may use files with the same extension for different types of data.

DiscFerret Disk Image

We know that one DFI format is DiscFerret Disk Image. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

DiskFactory32 Disk Image

DiskFactory32 Disk Image files store raw, sector-level copies of floppy disks made using the DiskFactory32 utility. They capture every sector of the source disk - including damaged or unreadable areas - so the disk's exact data structure is preserved. Such images are useful for archival purposes or making duplicate physical disks with identical contents.

The format is created by DiskFactory32, a shareware floppy copying and imaging utility by Mark McGinty. It offers two modes: one that writes a full DFI image with its header, and another "raw" mode that omits the DFI header and just captures sector content. After image creation, the DFI form can be written back to floppy disk using the same program. Because DFI stores bad sectors and physical damage, it is more faithful than many simpler file-system-level or logical copies.

At the start of each DFI file there is an ASCII signature at offset 0: bytes "000800004469736B466163333220496D616765", which reads in ASCII (after some leading non-printables) as "DiskFac32Image". That signature helps software recognize the file as a DiskFactory32 Disk Image.

Dreamload File Archive Image

Dreamload File Archive Image files are archive containers developed to package multiple files together for use with DreamLoad software, a loader system commonly employed with MMC64-enabled Commodore 64 hardware. They bundle game binaries, level data, documentation, and other resources into a single file so that DreamLoad and its MMC64 plugin can manage, display, and start individual components of a release from within the archive rather than requiring separate disk images.

This format is produced by creators who build releases for the DreamLoad system (notably Doc Bacardi / The Dreams). Files are converted from standard Commodore-64 filesystems or disk images into this archive format so the MMC64 firmware's DFI plugin can present a directory listing for the archive. Once the user selects a file from the archive, DreamLoad's driver supplies it to programs as though it were loaded from a traditional disk image.

Files begin with the ASCII header ".DREAMLOADFILEARCHIVE" at offset zero. At offset 0x17 there is a byte zero terminator which helps define the header's end. Additionally, a little-endian 16-bit version number follows the header, along with a little-endian 16-bit field used for internal flags, then a 32-bit track count field later in the header.

Various apps that use files with this extension

These apps are known to open certain types of DFI files. Remember, different programs may use DFI files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about DFI file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.