BCM File

What are BCM files and how to open them

Are you having problems opening a BCM 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 BCM files.

What is a BCM file?

A .BCM file is a BCM Compressed Archive file.

BCM Compressed Archive files are losslessly compressed archives produced by the open-source compressor bcm, created by Ilya Muravyov. They serve to pack and compress any kind of file data - documents, logs, binaries, etc. - into a single, compact archive, using a Burrows-Wheeler Transform based engine that trades off speed, memory usage, and compression ratio depending on chosen block size and compression mode.

The bcm program writes these archives; it offers options to set block sizes via parameters like -b to control how much data is processed per block. Larger blocks typically yield better compression at the cost of higher RAM demand. During use, files are compressed with bcm then extracted back to their original byte-for-byte form by the same tool.

Internally, these archives begin with an ASCII signature at the very start of the file. The first bytes are "BCM!" (hex 42 43 4D 21) at offset zero, which serves as an identifier.

How to open BCM files

Important: Different programs may use files with the BCM file extension for different purposes, so unless you are sure which format your BCM 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 BCM openers which you will find listed below.

Last updated: August 23, 2026

Various apps that use files with this extension

These apps are known to open certain types of BCM files. Remember, different programs may use BCM 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 BCM file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.