What Does Binhex Mean?

BinHex is an encoding system used in converting binary data to text, used by the Macintosh OS to send binary files through email. Conversion of binary data into ASCII characters is done to easily transfer the files from one platform to another, as almost all the computers can handle ASCII text files.


BinHex was originally the idea of Tim Mann. He wrote it for the TRS-80 as a stand-alone version of an encoding system. BinHex is similar to Uuencode (Unix to Unix encode) and is a common format for Macintosh files. BinHex files need more space than the original format files and are less likely to be corrupted while in transit between older protocols.

A BinHex file generally has a .hqx extension at the end of its filename. Earlier versions had the extension .hex.

This term is also known (referenced) as .hqx.

Techopedia Explains Binhex

BinHex generally encodes an 8-bit binary file, or 8-bit stream representation, into a 7-bit ASCII text format. When a file is transferred on a network as an email attachment, the recipient at the other end has to decode it. A number of decoders are available to decode BinHex files for both Windows and Mac OS. Stuffit Expander is a free and simple application, which can decode, encode, compress, and archive files.

BinHex is very useful for Mac OS 9 and earlier versions of Mac OSs, because it combines both data and forks of a file system and keeps them bundled during transfer. A BinHex file contains a message on the first line, which helps to identify it as a BinHexed file. This message is followed by 64-character lines, which may include random letters, numbers, and punctuation marks.

BinHex was originally used for sending files through online services like CompuServe, whose pipes were not often 8-bit clean and needed a 7-bit stream. This problem was addressed in the mid-1980s when CompuServe added the 8-bit clean file transfer protocols. The use of BinHex was then stopped. However, there were still file upload problems on CompuServe and the need for BinHex to address the problem was recognized.

In 1985, Yves Lempereur released BinHex 4.0, which addressed problems, such as incompatibility, file destruction, and file corruption. BinHex 4.0 took extra care in choosing character mappings to avert characters translated by the email software. It encoded even the file information and protected it with multiple cyclic redundancy checks. The final .hqx files were more robust and were almost the same size as the .hcx files. Some of the popular Web browsers, like Netscape, and email applications, such as Eudora, supported BinHex capability for encoding and decoding files.


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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.