This article is from the Mac
communications FAQ, by Bruce L Grubb BruceG6069@aol.com with
numerous contributions by others.
09 What do file suffixes like .hqx, .sit, .bin, etc ... mean and how can I convert such files back to normal Macintosh applications and documents? (File Formats and Conversion - Macintosh)
Most files available by FTP or posted to Usenet are modified twice to
allow them to more easily pass through foreign computer systems.
First they are compressed and then either ASCII or Binary encoded with
BinHex (.hqx) and MacBinary (.bin) being the formats of choice for
Macintosh users (see [2.3] and [2.4] for an explanation of these
Generally the suffix on these files only tells you the encoding
method used and nothing about the compression method. As a result
StuffIt Expander has become the defacto decoder utility. You can
use the following table to determine what Macintosh programs handle
This table is also part of the Mac-Site-list and listed on its own as
format-chart.txt both of which are at
as well as being archived on any info-mac mirror site, in the
Here's a handy chart to keep track which programs unmangle which formats:
unix gzip .uu/ .b64/
Macintosh .sit .hqx .bin .zip .tar .Z .gz/.z .uue .mime*
Stuffit Expander** D D D D D D D D D
DropStuff** C C
DropTar** C C C C
DropZip** I C C
StuffIt Deluxe*** X X X X X X X X D
MacGzip D X
MPack 1.5.1 D D X
Rosetta D D D D
SunTar 2.2.3 X X X X D
ZipIt D D X
Other unix gzip .uu/ .b64/
computers .sit .hqx .bin .zip .tar .Z .gz/.z .uue .mime*
Stuffit Expander** D D D D D D
StuffIt Standard** X X X X X X
StuffIt Deluxe (Win)*** X X D X X D X X X
Expander (Linux) D/N D D D D D D D
StuffIt (Linux)*** C/N C C C C C C
MPack D D X
xferp110 (win) X X X
D = Decode/decompress only
C = Create/compress only
I = MacBinary format is supported internally only
X = Create and decode
N = cannot handle new sitx format
.sit refers to all versions of the Stuffit format. A '/' denotes the
inability to handle certain formats as outlined in the legend above.
.hqx = BinHex4; .bin = BinHex5, MacBinary I, II, and III
Note: Almost every Mac communications program can decode .bin files.
* .b64/.mime (Base 64) refers to the encoding format used by the
Multipurpose Internet Mail Extension. For more information consult
the MIME FAQ.
** Stuffit Expander (free) along with DropStuff, DropTar, and DropZip
(shareware) are combined into StuffIt Standard.
Current public versions are 7.0.0 (Mac) and 8.0/7.5 (Win)
*** Current versions as of this writing are 7.0 (Mac), 7.5 (Win)
and 5.2 (Linux and Solaris)
Aladdin has a more detailed format chart at their site
Note: .gz and .Z compression systems, while both native to UNIX, are
completely different, and these suffixes cannot not be interchanged.
WARNING: .hqx, .uu, .b64, and .txt files are the ONLY files that can
be downloaded in ASCII mode; all others must be downloaded in BINARY
[IMAGE] mode for the file to decompress properly. This is especially
true of ".bin" and "unstuffed" files. Otherwise you will get errors
like "unreadable file" or "file is corrupt" when you try to decompress
Less commonly used formats. Those followed by a + are Mac formats.
old (c1990) MS-DOS compresion format, replaced by .zip.
Decompressed by Stuffit Expander/Deluxe, and MacArc.
PC format common to European sites. Decompressed by unArjMac,
DeArj, and StuffIt Expander/Deluxe 7.0.
Mac compression format created by Compact programs (last
updated April 1995). Decompressed by Stuffit Expander,
StuffIt Deluxe, Compact Pro, and macunpack.
Disk Doubler (Mac) format. Decompressed by DDExpand, DiskDoubler
and Stuffit Expander 6.0.
DOS/Windows executable file (program); also used to create
self-extracting archives. An .exe file used as a self-extracting
archive can usually be decompressed with Stuffit Expander.
Use of this format of an archive is strongly discouraged as it
can cause problems crossplatform.
WWW document. Used by WWW browsers such as Netscape and Explorer.
.image/.img/.ima/ (related format - .smi, .dmg)
These are all disk image extensions. They represent Mac disk image
(.image/.img), Microsoft Disk Image Utility (.img), Winimage
(.ima), and MacOS X disk image (.dmg) formats. Disk Copy can
handle all these formats. .smi is a self mounting disk image
format that has been made redudent with MacOS X.
Note that .img is also used as an graphic file extension and
needs GraphicConverter to view.
.lzh (related formats - .lha and .lzs)
old PC/Amiga format that is still quite popular in Japan and
with Aminet Amiga site <http://us.aminet.net/~aminet>, largely
replaced by .arc and .zip elsewhere; decompressed via
Stuffit Expander 7.0, LHA Expander 1.0.3, and
French KISS 2.2.0. StuffIt Deluxe 7.0 and MacLHA 2.2.1 can
compress in the lha format.
AppleLink package format currently only used for MacOS X
installers. Handled automaticaly by Mac 10.1 and higher.
A DOS compression format. Handled by MacRAR <http://macrar.free.fr/>
StuffIt Expander/Deluxe 7.0.
A special version of a Mac compression format that decompresses
itself when opened. The most common .sea files are Stuffit,
Compact Pro, and Disk Doubler. Use of this format is strongly
discouraged as it can cause problems crossplatform.
Unix shell archive. Decoded by Unshar.
another name for .tar.Z
another name for .tar.z and .tar.gz (do not confuse with .tar.Z)
The term tarball (which refers to any tar file) has also been
used to describe this.
.txt (.abs, .doc)
ASCII text file. There is a slight differance between ASCII text
files of Mac, PCs, and UNIX systems which can cause problems when
trying to read them. Mac ASCII uses carrage returns, UNIX uses
line feeds, and PC uses both.
Suffix used by both Unix pack and early (c1993) Gzip files.
Due to confusion between these compression methods and Unix
'compress' suffix (.Z) it was abandoned in favor of
the .gz suffix. Unix pack itself has been effectively
replaced by both Unix compress and Gzip.