BM File

What are BM files and how to open them

Are you having problems opening a BM 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 BM files.

What is a BM file?

A .BM file is a Bennet Yee's Face Format Bitmap file.

Bennet Yee's Face Format Bitmap files store simple monochrome images intended for use with the "face" and "xbm" programs written by Bennet Yee. Their primary purpose is to represent small face-icons or bitmaps in a compact binary form, readable by tools like Netpbm, especially for conversion to and from PBM format.

These bitmaps are created by programs that generate images in one bit-per-pixel (black and white) form, with width and height specified in their headers. They are intended to be converted via Netpbm tools (for example ybmtopbm to go from Bennet Yee's face format to PBM, and pbmtoybm for the reverse) when interoperability with more common image formats is needed.

Files begin with a two-byte signature: the ASCII characters "!!" (bytes 0x21 0x21) at the very start (offset zero) indicate that the file is this format.

How to open BM files

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

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

Last updated: August 24, 2026

Various apps that use files with this extension

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