BNY File

What are BNY files and how to open them

Are you having problems opening a BNY 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 BNY files.

What is a BNY file?

A .BNY file is a Binary ][ Archive file.

Binary ][ Archive files preserve Apple II files together with their system attributes for safe transmission or storage. These archives wrap one or more ProDOS‐format Apple II files into a single container which retains metadata such as the filetype, auxiliary type, modification date, and storage mode; doing so prevents loss of those attributes during modem transfers or through bulletin board systems. Introduced by Gary B. Little around 1986 for use with his Modem MGR communications program, this archive format ensures Apple II files remain runnable after being sent through systems that would otherwise strip metadata.

The archive is produced by creating a header block of 128 bytes per file detailing its metadata, followed by the raw file data. If necessary, the data portion is padded with zero bytes so that its length aligns to a 128‐byte boundary. Multiple files are stored by concatenating headers and data blocks in sequence. Compression or encryption is not inherent to this wrapper format, though archive writers may compress file contents beforehand, e.g. using Squeeze, and then wrap the result in this format.

Records describing each file include ProDOS type codes, auxiliary types, storage types, block counts, modification dates, and a count of how many files follow (zero for the last). Partial pathnames may be used in filenames, but complete pathnames are not permitted. The format's identifier or "magic" signature starts with the byte sequence 0x0A, 0x47, 0x4C at offset 0 in the header.

How to open BNY files

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

While we have not verified the app ourselves yet, our users have suggested a single BNY opener 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 BNY files. Remember, different programs may use BNY 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 BNY file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.