CFL File

What are CFL files and how to open them

Are you having problems opening a CFL 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 CFL files.

What is a CFL file?

A .CFL file is a Compressed File Library Compressed Data file.

Compressed File Library Compressed Data files hold an archive of resources combined into a single file with optional compression and encryption, designed to reduce file access overhead. They are produced by the Compressed File Library (CFL) system, a public-domain engine written in C++ that serves as a virtual file system, chiefly for games. CFL files bundle game assets - textures, models, sounds - so a program can load multiple resources from one container instead of many separate files.

The engine is used in Fathammer's X-Forge and in IMVU for packaging 3D character models and accessories. Creation of a CFL file involves gathering resource files, optionally compressing and encrypting them, then writing them into a CFL archive. Reading involves indexing the contents and accessing individual entries via offsets. The library includes tools like "makecfl" to build CFL archives, and a version called CFL3 adds features such as plugin compressors, preprocessors, and ciphers.

Files usually begin with an ASCII signature of four letters: "DFL3" or a similar marker identifying the CFL version. Immediately following is a header with an offset, format version code, and a length field indicating how much compressed data follows. Inside the compressed or uncompressed data section there is a sequence of entry records: each entry has a size, an offset to its data, a compression type identifier, a short name length, then the name, followed by the content data. If entries are compressed (for example using LZMA), the entry data is decompressed according to its stored type.

How to open CFL files

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

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

Last updated: August 31, 2026

Various apps that use files with this extension

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

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