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Other Links and Notes

The file name extension is the three character designation appended to file names in windows systems. E.g. .doc for MS Word, .txt for plain text files, .gif .jpg and others for graphic image formats. Windows and Internet browsers use these to determine what application to open to read a file. There are many file types (over 15,000 are listed at filext.com/).
This is a list of 750 of the most common ones, which I started in 1994 to configure web servers so clients would open the correct application to read files on the web.

Since there is no central registry there are quite a few duplicates (same extension for different files). For example there are 20 different file types with an extension of .img, 18 with .art, 16 with .db and more than 20 with an extension of .dat. Only the most common use of each extension is shown. Click on the extension for a more complete list.

File extensions ending in "_" (e.g. .38_) are usually compressed files in an Install package which are expanded (e.g. to .386) by the installer.

See filext.com The File Extension Source for others. see also File Extension Help at filext.com. It explains how to get clues as to a files type based on where you got it or where it is stored on your hard disk.

The first several characters in a file may be used to determine the type of file. This may be useful if the file was created on UNIX or a Mac where the file name extensions are not required. See type-from-content below.

Multipurpose Internet Mail Extensions (MIME) types are included in the file message header by web servers. Browsers uses this to determine what program to use to display the file contents.
See MIME for more information.
The association between etensions, MIME-types and application programs is configured in windows from a "my compuer" or "windows explorer" window by selecting View > Folder Options > File Types. On macs and UNIX they are set up in your browser (e.g. Internet Explorer) under Preferences > Receiving FIles >Helpers.
Or on a Mac: Select the document and choose File > Get Info. click to show the "Open with" pane.

750 of the most common ones are listed below. See filext.com/ and Dot What!? for lists of over 15,000.

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File Extn MIME Type Start
386 application/octet-stream   Windows Enhanced Mode Driver or Swap File
001 application/x-001   FAX Datafile
0xx     Electronic Navigational Charts (ENC) S57, or DX90 Cells
3gp or
audio/3gpp, video/3gpp   3rd Generation Partnership Project. Multimedia over 3rd generation wireless networks. H.263 video is the mandatory video format in 3GPP and AMR is the main audio/speech format.
7CB application/vnd.ecdis-update   Electronic Chart Display and Information System (ECDIS) ENC DirectENC files
7z     7-Zip Compressed File
aa audio/audible   Audible file format (audio books)
aab application/x-authorware-bin   Macromedia Authorware Binary
aac audio/aac   Advanced Audio Coding File. Part of MPEG-2 and MPEG-4 standard. (Apple iTunes Store)
aam application/x-authorware-map   Authorware Map (Shockwave?)
aas application/x-authorware-seg   Authorware Shocked Packet (Segment)
aba text/x-palm-aba   AddressBook Archive (Palm)
ac3 audio/ac3   Adaptive Transform Coder 3 (relates to the bitstream format of Dolby Digital)
aco     Adobe Color
acsm     Adobe Content Server Message File - overdrive e-Book for reading in Adobe Digital Editions
act     Office Actor or Animation Work Actors or Photoshop Color Table File
adi     AutoCAD Plot File
adr application/x-msaddr   Address Book
aexpk application/pgp-keys   Armored extracted public key (PGP)
afl video/animaflex   Font file (for Allways) (Lotus 1-2-3)
ahtml magnus-internal/cgi-advertiser    
ai application/postscript   Encapsulated PostScript (metafile) (Adobe Illustrator)
aif audio/x-aiff   Audio Interchange File Format
aifc audio/x-aiff   Audio Interchange File Format
aiff audio/x-aiff   Audio Interchange File Format
aim application/x-aim   AIM file - AOL Instant Messanger
ale     Apple Lossless Encoder (same as m4a)
alt application/x-up-alert   Menu file (WordPerfect Library)
aml     Arc Macro Language
amr     Adaptive Multi-Rate Codec. Speech encoding format used in GSM telephony.
ani  animated cursor
ans     MS Word for Windows Text with Layout
aos application/x-nokia-
  Add-On Software (Nokia 9000)
ape     Monkey's audio Lossless Compression format
apk application/vnd.android.package-archive   Android Package File - A zip format containing files .DEX, .ARSC, and AndroidManifest.xml to run in an android program.
apnx   Amazon Page Number Index File
app     Apple Macintosh Application bundle
app     dBASE Application Object File
arc     PC ARC Archive compressed
arj application/x-arj   Compressed file archive created by ARJ or winzip
art image/x-jg, image/art   AOL Johnson-Grace Compressed File and Another Ray Tracer Format
as     AppleSingle
asc   ASCII text
asc   ActionScript Communication File - Adobe
asc application/pgp-encrypted   Armored Encrypted file (PGP)
asd application/astound   Autosave file (Word for Windows)
asf application/vnd.ms-asf video/x-ms-asf video/x-ms-wm   Windows Media file - Advanced Systems/Streaming Format (ASF), NetShow
ashx     ASP.NET Web Handler File
asm     PC ASM File
asn application/astound    
asp text/html, text/asp, application/x-asp, application/x-asap   Active Server Pages - standard HTML documents interlaced with ActiveX script code
aspx     Part of Microsoft .NET; a webpage source file. Chase Visa Statements read with Adobe Acrobat (really a pdf file). Create with Dreamweaver MX or Microsoft Visual Studio
asp     File type created by the Association of Shareware Professionals.
asr video/x-ms-asf   Microsoft NetShow
asx video/x-ms-asf application/x-mplayer2 application/asx   Advanced Stream Redirector File (Microsoft)
asz application/astound    
atrac     Adaptive TRansform Acoustic Coding audio file
att     AT&T Group 4
au audio/basic, audio/x-ulaw, audio/x-gsm, audio/snd   8-bit u-law [PCM] / 8000 Hz
aux   ArcGIS Auxilliary File
avi video/avi, video/msvideo, video/x-msvideo   Audio Video Interleave File - Windows Media Player, RealPlayer. May use sevral Codecs such as VfW (Video for Windows). Some Codecs are not supported on the Mac.
See: John McGowan's AVI Overview
avr     sound
avs     animation
awe     pAcrobat Bookmark XML File
awk   BOBO AppleWorks or UNIX awk script
axd text/plain   ASP.NET Web Handler File
axs application/olescript   ActiveX Script
azw application/octet-stream   Amazon Kindle e-book File

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File Extn MIME Type Start
b64     WinZip
bac     binary backup
bak     Backup file
bas text/plain   BASIC program
bat application/octet-stream   DOS BAT (Batch) file.
bbm     image
bck     VMS backup
bcpio application/x-bcpio   Old Binary CPIO
bexpk application/pgp-keys   binary extracted public key (PGP)
bfc     briefcase
bib     BibTeX Bibliography
big     Chinese Traditional text coding (old version)
big5     Chinese Traditional (old version)
bin application/octet-stream   Uninterpreted Binary Data
bin application/x-macbinary   Binary file
bk application/vnd.framemaker   FrameMaker book
bleep application/bleeper    
bmf     Binary Material File
bml     Bean Markup Language, a set of Java classes that provide scripting language.
bmp image/x-bmp, image/x-MS-bmp, image/x-mspaint, image/x-win-bmp   Windows Bitmap (PaintBrush)
boo     image
brw     Oracle Browser
bst     BibTeX Style Files
btf image/prs.btf   NationsBank Check Images (also .btif)
byu     movie byu file
bup     Backup DVD Info File
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c text/plain   C program
c++ text/plain   C program
cab application/cab, application/x-cabinet-
  Cabinet file Microsoft installation archive. opersyss=win32, mac cpu=x86, ppc, mips, alpha
cag     Clip Art Gallery - PowerPoint
cal application/x-msschedplus   MS schedplus or calendar
cat application/pdf   PDF Catalog (Used with Acrobat Reader and Search plug-in)
cat application/vnd.ms-pki.seccat   Security Catalog
cat     Quicken IntelliCharge Categorization File
cch     Corel Chart
ccs text/ccs   Cluster Configuration System used with the Global File System (GFS) in Red Hat Linux
cdda audio/aiff   CD Audio Track
cda audio/x-cda   CD Audio Track
cdf application/x-netcdf   Channel File, Unidata netCDF data file
cdf text/plain, application/x-cdf   Channel Definition Format - MS push std
cdr     ISO CD/DVD Disk Image File on a Mac (see also .iso, dmg, cso, dax)
cdr application/x-coreldrw   Corel Draw (metafile)
cer application/pkix-cert, application/x-x509-ca-cert   Internet Security Certificate
cfg     Configuration file used by many programs. No standard format.
cfl     COREL flow
cfm wwwserver/wsapi   Cold Fusion Markup
cfs     ColdFusion IIS plugin IICF.DLL)
cgi magnus-internal/cgi, wwwserver/shellcgi   Common Gateway Interface
cgm image/cgm   Computer Graphics Metafile ISO/IEC 8632
chat application/x-chat    
che application/x-up-cacheop    
chm     Compiled HTML
cht audio/x-dspeech   Chart (Harvard Graphics 2.0 - SoftCraft Presenter)
cil application/vnd.ms-artgalry   Clip Gallery Download Packages
class application/java-vm, application/octet-stream   Java
cli application/vnd.ms-artgalry    
clm     Magic Jack call log
clp image/x-clp   Clip art graphics (Quattro Pro)
clp application/x-msclip   Windows Clipboard (metafile)
cmd     Windows NT and 95 CMD files (similar to bat in DOS)
cmf     music
cmx drawing/cmx
  Corel Presentation Exchange, Corel Metafile Exchange
cnc application/x-cnc   CNC general program /fsta
cnf     converter
cnt     Help File Contents
cnv     Canvas Ver 6, 7, ... Image (free Canvas 9 Viewer at ACD Systems)
cnv     Word Data Conversion File
cod image/cis-cod   Datafile (Forecast Plus - MS Multiplan - StatPac Gold)
coda application/x-coda    
com application/octet-stream   DOS COM Executable (similar to exe, but a direct memory image)
con     QuickTime .mov on Disney server returns extension .con or.c
conf     Configuration File - Linux
cpi     Windows or DOS International Code Page
cpi image/cpi   ColorLab Processed Image
cpio application/x-cpio   IEEE Std1003.2 (`POSIX') CPIO
cpl     Control Panel extension
cpp     C++ source files
cpt application/mac-compactpro   Compact Pro Archive
cr2   Canon Raw Image Format
crd application/x-mscardfile   MS cardfile
crt application/x-x509-ca-cert   Certificatefile
crx   Chrome Extension
csh application/x-csh   CSH Script
cso     CISO Compressed ISO disk image (DevHook & PlayStation (psp) iso compressor application)
css application/x-pointplus   Datafile (CSS - Stats+)
css text/css   Cascading Style Sheets
csv text/csv, application/csv, application/x-csv   Comma-Separated Values (Excel, Lotus 123, FoxPro, MS Outlook)
ct image/   Iris CT Graphic or Scitex CT Handshake Bitmap
cu application/x-cu-seeme    
cur     cursor image
cut image/x-halo-cut   Bitmap graphics
cv5     Canvas Version 5 Image
cwk   BOBO Claris Works or AppleWorks
cxt     Macromedia Director Protected Cast File
cxx     C++ source files

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Movie Encoded with DivX-codec
File Extn MIME Type Start
dat application/octet-stream   Data file. Can be anything, text, graphics, binary, ...
dat application/ms-tnef   MicroSoft Transport Neutral Encapsulation Format. When an end user sends mail to the Internet from an Exchange Windows or Outlook client (not outlook express), a file attachment called WINMAIL.DAT may be created with Exchange Server RTF information for the message. Programs like WMDecode and Fentun can be used to recover any attachments from the WINMAIL.DAT file. Some mail programs will automatically extract the contants e.g. a MS Word (.doc), Excl (.xls), Windows Media Video (wmv) or other binary document.
dat     Digital Audio Tape. Get VLC Media Player at www.videolan.org/ for Mac
dat video/dvd, video/mpeg   Video CD MPEG or MPEG1 Movie
db   Database. There are at least 16 different applicataion using the extension, usually for a database file.
dba text/x-palm-dba   DateBook Archive (Palm)
dbf application/octet-stream   DataBase File (FoxPro, dBase)
dbm wwwserver/wsapi   ColdFusion IIS Plugin
dca application/dca-rft   IBM Doc Content Arch
dcf     dKart Charts www.openecdis.org
dcr application/x-director   Macromedia Director (Shockwave)
dcr     digital camera - Kodak Digital Camera Raw Image File
dcs     image
dct     Dictionary file used by various programs (Adobe Illustrator, Clarion, .. )
dct     Express Dictate's audio file (Note: DCT - discrete cosine transform, is a pict and video compression algorithm which is different)
ddb     Device-Dependent Bitmap
ddf     Dynamic Data Format (http://www.stsci.edu/stsci/meetings/adassIV/conroym.html)
deb application/octet-stream   Binary for debian UNIX
der application/x-x509-ca-cert   Certificatefile
des     text
dex     Bytecode to run in the Android Runtime (ART) virtual machine.
dfont     Mac Datafork TrueType Font
dib     Device Independent Bitmap. A .BMP file without .BMP header.
dic     Dictionary
dif     Data Interchange Format - a general spreadsheet format
dig     text
dir application/x-director   Macromedia Director (Shockwave)
divx     Movie Encoded with DivX-codec
djv image/vnd.djvu   Movie Encoded with DivX-codec
djvu image/vnd.djvu   DJVU image (AT&T compression)
dl     PC DL Movie
dlg     image
dll application/x-msdownload, application/x-pe-
  Dynamically Linked Library (DOS) pe-portable executable opersys=win32, mac cpu=x86, ppc, mips, alpha
dl_     compressed .dll in Install package
dmg     Disk Image (Apple)
dms application/octet-stream   Compressed Amiga file archive created by DISKMASHER
dng     Digital Negative - Adobe
dnl     DNAML e-Book File. Protected using
digital rights management (DRM)
dnp     DRM File
do   Stata Batch File
doc application/msword, application/doc   MS Word
docx application/presentations, application/doc   Word Microsoft Office Open XML Format Document (Office 2007)
dot application/msword   MS Word (Template)
dox     Multimate 4
dp     DAVIN
drv     Device Driver
drw     Micrografx Designer 3.1 (metafile)
dsf image/x-mgx-dsf   Micrografx Designer 6 (metafile)
dsp     Rumba TN3270 session profile
dst application/tajima   PC-RDist Distribution file
dta   Stata Data File
dtd text/xml   SGML Document (Type) Definition file
dtl   Django Template Language
dus audio/x-dspeech   Readiris font dictionary
dvi application/x-dvi   TeX DVI (Device Independent)
dwc application/dwc   compressed archive
dwf drawing/x-dwf   Autodesk WHIP! Drawing Web file
dwg application/x-acad, application/vnd.dwg, image/vnd.dwg, application/x-dwg, application/x-autocad   AutoCAD Drawing
See History of CAD
dwg     Drawing (Drafix)
dwt  DreamWeaver template and AutoCAD Template/Prototype
dxf application/vnd.dxf   Drawing eXchange Format, Data Exchange File, AutoCAD (vector)
dxr application/x-director   Macromedia Director (Shockwave)

E-F -> A | B | C | D | E-F | G-H | I | J-L | M | N-O | P | Q-R | S | T-U | V | W | X-Z

File Extn MIME Type Start
ebk application/x-expandedbook    
ece     used by the The Independent News in the UK. May be some kind of scripting language.
efx     eFax Fax Document (J2 Global Communications efax.com
emf image/x-emf   Enhanced metafile created in Microsoft Windows and Visio 2002 applications
eml message/rfc822   MS Internet Mail Message (Outlook Express and others)
emlx message/rfc822   Mac OS X mail message
emz   .emf file compressed with gzip
enc application/pre-encrypted   Pre-encrypted Data (also Sniffer trace)
enex   Evernote export/archive
eot application/octet-stream   Embedded OpenType Font
eps application/postscript   Encapsulated PostScript (raster)
epub application/zip   Open e-book file. An XML format for reflowable digital books and publications. From the International Digital Publishing Forum. Actually a zip doc.
erf application/x-hsp-erf    
es audio/echospeech    
etf image/x-etf   Enriched Text file
etx text/x-setext   Structure Enchanced Text
euc     Japanese (Kanji)
evy application/x-envoy   Document (WordPerfect Envoy)
exe application/exe, application/octet-stream, application/x-msdownload   Directly executable program (DOS)
ex_     compressed .exe in Install package
exe application/x-pe-
  pe-portable executable opersys=win32, mac cpu=x86, ppc, mips, alpha
exif     Exchangeable Image File format for digital cameras. JPEG file with Exif metadata. Not actually an name extension but a special type of .jpg
exr     OpenEXR Image - Industrial Light & Magic
f     Freeze Compressed File Archive (UNIX)
fac     picture
fbc     FamilyTree Compressed Backup File
fdd   Parallels floppy disk image
fdf application/vnd.fdf   Acrobat Portable Document Input Form
fh4 image/x-freehand   Vector graphics (Aldus FreeHand 4.x)
fh5 image/x-freehand   Freehand 5
fhc image/x-freehand   Freehand
fif image/fif   Fractal Image Format file
fif application/fractals   Fractals
fits image   Flexible Image Transport System. GeoTIFF
fla application/x-shockwave-flash    
flac audio/flac   Free Lossless Audio Codec
flc video/flc   FLIC Animated Picture Autodesk
fld     fLd Player Video (YouTube videos). Flash type but may need separater fld player.
fli video/fli   FLIC Animated Picture Autodesk
flt     filter - e.g. Graphic inport filter for Word
flv video/x-flv   Flash Video File
flx   MicroSurvey CAD Drawing File
fm application/filemaker_pro   FileMaker Pro (also used with FrameMaker 3)
fm application/vnd.framemaker   FrameMaker Document
fm3 application/x-maker   FrameMaker
fm3   FileMaker 3 Database Document
fm3     Lotus 1-2-3 Format File
fm4 application/vnd.framemaker   FrameMaker
fm5 application/vnd.framemaker   FrameMaker
fml application/fml    
fon     Windows 3.x font library file
fot     Installed TrueType Font
fpbf     Finder Backup Burnable Archive - tar-format archives on Mac OS X
fpx     FlashPix format for storing digital images developed by Kodak
fp5 application/filemaker5   FileMaker Pro
frl application/freeloader   FormFlow file
frm application/vnd.framemaker   FrameMaker
fs application/X-FSRecipe    
fssd     sound
ftw     FamilyTree Maker

G-H -> A | B | C | D | E-F | G-H | I | J-L | M | N-O | P | Q-R | S | T-U | V | W | X-Z

File Extn MIME Type Start
g3f image/g3fax   Group III FAX
gb application/chinese-gb
  Chinese Text
gds     image
gdb     GeoDatabase, GPS Database
ged     GEDCOM Family History File
gem     Venture Publisher, GEM Draw (vector)
gif image/gif GIF GIF - Graphics Interchange Format - Compuserve (raster)
gl     animated picture
gmf     graphic
gph   Stata Graph File
gpx     GPS eXchange format. EasyGPS
gry     picture
gsc     GeneStudio File - (Molecular Biology Software)
gsd audio/x-gsm   GSM Internet Realtime Audio
gsm audio/x-gsm, application/x-gsm   Raw GSM 6.10 Audio Stream
gtar application/x-gtar   Gnu Tar
gz application/x-gzip, application/x-compressed   Unix Gzip (gnu-compress ecnapsulation)
gzip     compressed
h     C Header
ha     compressed
ham     image
hdd   Parallels Desktop Hard Disk File
hdf application/x-hdf   NCSA HDF (Hierarchical Data Format)
hdml text/x-hdml    
heic     iOS High Efficiency Image Format
hgl     HP Graphics Language
hlb vms/help   VMS help libraries
hlp application/x-mshelp   Windows Help
hpgl application/vnd.hp-HPGL   HP Graphic Language
hpk     compressed
hqx application/mac-binhex40   BinHex 4.0 Format - Macintosh Binary to ASCII conversion.
hrz     image
htm text/html   HTML - HyperText Markup Language
html text/html   HTML - HyperText Markup Language
htt     Hypertext templates. GoLive, FrontPage
htx     Extended Hypertext Template - MS HTML extension files
hyp     compressed
hz application/chinese-hz   Chinese

I -> A | B | C | D | E-F | G-H | I | J-L | M | N-O | P | Q-R | S | T-U | V | W | X-Z

File Extn MIME Type Start
ibm     picture
ica application/x-ica   Bitmap graphics (Image Object Content Architecture)
ice x-conference/x-cooltalk   Cooltalk Audio
icm     Image Color Matching File
ico image/ico, image/x-icon   Windows icon
icq application/x-icq   Saved ICQ Contact Information. From IRQ Chat Groups, Lists, Boards, Lists, IrCQ-Net Chat.
ics text/calendar   Calendar Data (iCal - Mac; Outlook or Windows)
idc     Internet Database Connector
ief image/ief   Image Exchange Format
iff image/iff   Amiga Bitmap Graphic
ifo     DVD Info File
model/iges   Initial Graphics Exchange Specification. ANSI-approved standard format used with 3D wire frame models.
Mac: CADintosh from Lempesoft.com or Win: igsviewer.com
igs model/iges, image/x-igs, application/iges, application/x-igs   IGES - Initial Graphics Exchange Specification Format
img image/img   Venture Publisher, GEM Draw (bit mapped), AutoCAD CAD-Camera, others
img     Apple Macintosh Disk Copy Format, HDCopy Pro hard disk images
imi     Magellan GPS detailed map
ini text/plain   Initialization/Configuration File for MS Windows. Many programs now use the registry (Windows NT and later) instead of .ini files.
inc text/plain    
indd     InDesign Document (Adobe)
inf application/x-setupscript   Setup scripts (For Installing Drivers, etc.), Autorun - auto-start file for a CD-ROM
ins application/x-NET-Install   Data (WordPerfect)
ipix     Interactive Pictures www.ipix.com
ips application/ips, application/
  Game Patch file
ipx application/x-ipix   IPIX AV file
isapi wwwserver/isapi   Internet Server API - Application Program(ming) Interface
ish     compressed
iso     Disc Image saved in ISO-9660 format (Easy CD Creator, Nero, Roxio)
ivr i-world/i-vrml   Virtual Reality World Live Picture
iw4     DjVu File

J-L -> A | B | C | D | E-F | G-H | I | J-L | M | N-O | P | Q-R | S | T-U | V | W | X-Z

jar application/java-archive    
jas     JASC JAS Compressed : Bitmap graphics
java text/plain    
jbig     image
jfi     image
jfx application/octet-stream   eFax Fax Document (J2 Global Communications jconnect.j2.com/
jis     Japanese
jpc     picture
jpe image/jpeg   JPEG-JFIF - Joint Photographic Experts Group
jpeg image/jpeg   JPEG-JFIF - Joint Photographic Experts Group
jpg image/jpeg   JPEG-JFIF - Joint Photographic Experts Group (raster)
jps image/x-jps   Stereo Image
js application/x-javascript   Java Script
jsc application/x-javascript-config    
json aplication/json   Java Script Object Notation
jsp magnus-internal/jsp   Java Script
jspx   XML Java Server Page
jso   Compressed disk image - PSP ISO Compressor
key application/
  Mac iWorks keynote presentation program. Includes slides, images, text, transitions.
kf8   Kindle Format 8 - Kindle fire e-Book format
kml application/vnd.google-earth.kml+xml   KeyHole Markup Language (Google Earth, ArcGIS Explorer, MS Virtual Earth)
ksh     K (Korn) shell
la audio/nspaudio   Netscape Packetized audio
lam     streaming audio metafiles
latex application/x-latex   LaTeX Source
lbm     image
lbr     library compressed
ldif text/x-ldif   LDAP Data Interchange Format ( Netscape Address Book)
lex   Lexicon (Dictionary)
lha application/octet-stream   LHA Archive
lis     program listing
lgo     Modern ListGeo Output. GeoTIFF
lm8     picture
lma audio/nspaudio   Netscape Packetized audio
lng   Acrobat Language Plug-in
loc application/octet-stream   GPS Location File - TopoGrafix
loe application/vnd.framemaker   FrameMaker list of exhibits
lof application/vnd.framemaker   FrameMaker list of figures
lot application/vnd.framemaker   FrameMaker list of tables
lpr   FrameMaker list of tables
or Homeworld
lpr   Kindle position informataion
lwp WordPro 9.5    
lzh application/octet-stream   compressed
lzs application/octet-stream   compressed
lzw     LHWarp archive
lzx application/octet-stream   compressed

M -> A | B | C | D | E-F | G-H | I | J-L | M | N-O | P | Q-R | S | T-U | V | W | X-Z

m13 application/x-msmediaview   MS mediaview
m14 application/x-msmediaview   MS mediaview
m2ts video/   Blu-ray BDAV MPEG-2 Transport Stream
m3u audio/x-mpegurl
  MP3 Playlist (Musicmatch, WMP, Winamp, ...)
m4a audio/   MPEG-4 audio file. Apple iTunes AAC and ALE unprotected
m4b audio/   MPEG-4 Audio Layer Bookmarkable File. Apple iTunes AAC and ALE unprotected
m4v     H.264 MPEG-4 Video File
m4p audio/   Apple iTunes AAC protected
m4b audio/   Apple iTunes AAC protected autiobook
ma application/mathmetica   Mathmetica Notebook
mac     Rumba VT420 (SPRY Telnet) TN3270 macro
mag     picture
man application/x-troff-man   Troff w/MAN Macros
map application/x-httpd-imap, magnus-internal/imagemap   Image Configuration File (HTML Image Map)
mat     sound
mbd application/mbedlet   Multimedia Builder Project File
mbp   Mobipocket Notes File
mcf image/vasa   Mathcad font
mcf     Meta Content Format File
mcw     MS Word in Mac format
md     compressed
mda application/x-msaccess   MS Access (May not be desirable)
mdb application/x-msaccess   MS access
mdf     SQL Server Master Database File
me application/x-troff-me   Troff w/ME Macros
med     Amiga Med Sound
mem     dBase Memory File
mesh model/mesh    
mfc     Microsoft Foundation Classes
mfp application/mirage    
mgf     image
mgi     Magellan GPS background map
mhg     multimedia
mht message/rfc822   Microsoft Web Archiv
mic     Microsoft Image Composer
mid audio/x-midi   MIDI
midi audio/x-midi   MIDI
mif application/vnd.mif, application/x-mif   Maker Interchange Format (FrameMaker)
mime message/rfc822   base64 (6-bit) is the standard for encoding binary attachme
mix     Microsoft Picture It
mk application/vnd.framemaker   FrameMaker
mki     picture
mkv     Matroska Video File
mlp     MacLinkPlus Print Capture File
mmf application/x-smaf
  SMAF = "Synthetic music Mobile Application Format" - Polyphonic Ringtone File for Phones - Yamaha
mmf     MS Mail file
mml     Maker Markup Language
mmm application/pdf   Acrobat Media Clip
mny application/x-msmoney   MS money
mobi application/x-mobipocket   Mobipocket e-book file, Gutenberg kindle book
mocha application/x-javascript   Java Script
mod     Amiga Mod Sound
mol chemical/x-mdl-molfile   MDL Molfile
mov video/quicktime   H.264 QuickTime digital video
movie video/x-sgi-movie   SGI "movieplayer" movie
mp2 audio/mpeg   MPEG Audio Stream, Layer II
mp3 audio/mpeg, audio/x-mpeg3,
  MPEG Audio Stream, Layer III
mp4 video/mp4v-es, audio/mp4   H.264 MPEG Audio Stream, Layer IV (QuickTime and RealPlayer)
mpa audio/mpeg   MPEG Audio Stream, Layer I, II or III
mpa text/x-palm-mpa   MemoPad Archive (Palm)
mpd     Windows Mini-port Driver
mpd   File List Creator MP3 Playlist
mpe video/mpeg   MPEG - Motion Picture Experts Group
mpeg video/mpeg   MPEG - Motion Picture Experts Group
mpg video/mpeg   MPEG - Motion Picture Experts Group
mpga audio/mpeg    
mpire application/x-mpire    
mpkg     Meta Package File - Installer archive (linus, Mac)
mpl application/x-mpire    
mpp application/vnd.ms-project   MS Project
mps     multimedia
mpt application/vnd.ms-project   MS Project
mpv application/vnd.ms-project   MS Project view
mpw application/vnd.ms-project   MS Project
mpx application/vnd.ms-project   MS Project
mrb     image
mrw     digital camera - Minolta Diamage Raw Image File
ms application/x-troff-ms   Troff w/MS Macros
msi text/mspg-legacyinfo
D0 CF Windows Installer File
msh model/mesh   2 and 2-D visualization
mso     MS Office Macro Reference File
msp     MS Paint
mspx     XML-based Web Page
mtm     sound
mtp     Microsoft Team Manager file
mts     MPEG Transport Stream - Advanced Video Codec High Definition (AVCHD) - High-definition MPEG Transport Stream video format
mtv     MTV Video Format File
mu     Mac UUencoded

N-O -> A | B | C | D | E-F | G-H | I | J-L | M | N-O | P | Q-R | S | T-U | V | W | X-Z

File Extn MIME Type Start
n2p application/n2p    
nc application/x-netcdf   Unidata netCDF data file
nef     digital camera - Nikon Digital SLR Cameras Raw Graphic File Format
nff     image
ngg     Nokia Group Graphics - Mobil Phone Logo
nol     Nokia Operator Logo - Mobil Phone
npx application/x-netfpx    
nsc application/x-nschat   Noder file (Polish)
nsf application/x-notes   Lotus Notes
nst     sound
ntf application/x-notes   Lotus Notes
    Mac iWorks spread sheet
nv     networked video
nws     Net News
nzb     newzBin USENET Index
obd     Office Binder file
obj     PC Compiled Object File
obt     Office Binder template
ocx application/x-oleobject   Object Linking and Embedding (OLE) Control Extension (ActiveX Control)
oda application/oda   ODA/ODIF ODF Open Document Architecture
odf     ODA/ODIF Open Document Architecture / ODF Open Document Interchange Format OpenOffice.org, Libre Office, StarOffice Calc
odg application/vnd.oasis
  OpenOffice/StarOffice ODF OpenDocument (Ver 2) Graphics Document
odp application/vnd.oasis
  OpenOffice/StarOffice ODF OpenDocument (Ver 2) Presentation
ods   ODF OpenDocument Spreadsheet - LibreOffice, OpenOffice
odt application/vnd.oasis.-
  OpenDocument Text - An open XML-based document file format for office applications to be used for documents containing text, spreadsheets, charts, and graphical elements. Approved as an OASIS (Organization for the Advancement of Structured Information Standards) Committee Specification. OpenOffice/StarOffice OpenDocument, LibreOffice
off     Object File Format, 3D images, (apps MeshLab, GLC_Player, RoffView
ofml application/fml    
ofx     Open Financial Exchange (Quicken, MS Money, ..)
ogg audio/x-ogg   Ogg Vorbis open-source audio format
ogv video/ogg   Video file that uses the Xiph.Org's open source Ogg container format
olb vms/olb   Vax Object Library or MS Project Object Library
omf     image
opd     OmniPage Document
opf     e-book Systems FlipAlbum
opw     Org Plus Org Chart
opx     MS Org Chart
or2 application/x-organizer   Lotus Organizer
orf     digital camera - Olympus Raw Image File
osd     Open Software Description - MS softwr distribution
ost     Offline Folder file
otf pplication/vnd.ms-opentype   Open Type Font
other     Unknown
ovl application/octet-stream   PC OVL File
owl     Web Ontology Language
oxt     OpenOffice.org Extension

P -> A | B | C | D | E-F | G-H | I | J-L | M | N-O | P | Q-R | S | T-U | V | W | X-Z

File Extn MIME Type Start
p12   Certificate file
p7c   Certificate file
p7m application/pkcs7-mime   S/MIME signedData, envelopedData
p7s application/pkcs7-signature   PKCS #7 Signature
p10 application/pkcs10   S/MIME Certificate Request
pac application/x-ns-proxy-autoconfig    
page application/x-coda    
pages PK   Mac iWorks pages word processor
pak     compressed
pal     Palettes
pat     Hatch patterns (AutoCAD - Photostyler)
pat     Vector fill files (CorelDRAW)
pbd application/vnd.powerbuilder6   Phone book (FaxNOW! - Faxit)
pbm image/x-portable-bitmap   PBM Bitmap Format
pcc     PC PaintBrush
pcd image/x-photo-cd   Kodak Photo CD (raster)
pcl application/pcl, application/x-pcl   Printer Control Language (HP)
pcm     sound
pct     Macintosh QuickDraw format (PICT) (metafile)
pcx image/pcx   PC Paintbrush (ZSoft Image)
pdb chemical/x-pdb   Chemical Objbect
pdb text/x-palm-pdb   Palm Database/Document File. Used by nook for e-Books
pdf application/pdf   Portable Document Format (Adobe Acrobat)
pdr     Port Driver
pds     Print Shop Graphic
pds     NASA Planetary Data System Format Space Mission Data
pem application/application/x-pem-file   Privacy Enhanced Mail Security Certificate
pf   Aladdin Systems Private Files Encrypted File or Archive file
pfm application/pdf   Acrobat Font
pfr application/font-tdpfr    
pgl     HP 7475A Plotter (vector)
pgm image/x-portable-graymap   PBM Graymap Format
pgp application/x-pgp-plugin   Support file (Pretty Good Privacy RSA System)
pgp application/pgp-encrypted   PGP Encrypted file
pgr text/parsnegar-document    
phl   Kindle Popular Highlights File
php application/x-httpd-php, text/php, application/php, magnus-internal/shellcgi, application/x-php   PHP Script
php   Host Presenter (Novell Telnet) profile
php3 application/x-httpd-php3    
phtml application/x-httpd-php   PHP Script
pic application/pic   Lotus Chart
pic image/pict   Macintosh QuickDraw format (metafile)
pict image/pict   Macintosh QuickDraw format (metafile)
pif application/x-mspif   Program Information File (Windows)
pit     Macintosh compressedB
pix     Inset Systems PIX (raster)
pjl     Printer Job Language
pkg     AppleLink Archive
pkr application/pgp-keys   Public Keyring (PGP)
pkt     EtherPeek Packet Dump
pl     Perl script
pls audio/x-scpls   MPEG PlayList (Real Audio, Napster)
plist   Property List XML File using Apple’s plist DTD (Document Type Definition)
plt     HP Plotter (HPGL) Print File
pm     PageMaker Document, Perl Module, Presentation Manager Graphic
pmd, pm3, pm4     PageMaker document
pnc text/x-palm-pnc   Palm Network Configuration File
png image/png, image/x-png   Portable Network Graphics (Replacement for gif with 65K colors) (lossless storage format)
pnm image/x-portable-anymap   PBM Anymap Format
pnt     MacPaint
pol     music
pot application/ms-powerpoint   MS PowerPoint template
pp     Amiga compressed
ppa application/vnd.ms-powerpoint   MS PowerPoint addin
ppm image/x-portable-pixmap   PBM Pixmap Format
pps application/ms-powerpoint   MS PowerPoint Slideshow
ppsx     Power Point Microsoft Office Open XML Format Presentation Slide Show
ppt application/ms-powerpoint   MS PowerPoint Presentation
pptx application/presentations   MS PowerPoint XML format (Office 2007)
ppz applications/ms-powerpoint   MS PowerPoint Animation
pqa text/x-palm-pqa   Palm Query Application
pqf application/x-cprplayer    
pqi application/cprplayer   Power Quest Drive imaging
prc application/vnd.palm   Palm Application
prc application/x-mobipocket   Mobipocket e-book file
prg     dBase program
prj     ArcView ESRI (Environmental Systems Research Institute) Coordinate System Definition
prl     Perl Script
prn     Fixed 'Print' file format, usually a space delimited values data file
pro     DOS Graphics Profile File
prn     HP Printer Control Language
prvkr application/pgp-keys   Private Keyring (PGP)
ps application/postscript   PostScript
psd application/x-photoshop   Adobe PhotoShop Document
psf     Photoshop Proof Setup
psid     picture/text
psr application/datawindow   Project Scheduler Resource file
pst     Personal storage/folder file
ptlk application/listenup    
pub application/x-mspublisher   MS publisher or PageMaker 2
pub   Ventura Publisher (Corel)
pubkr application/pgp-keys   Public Keyring (PGP)
push multipart/x-mixed-replace    
pvs   Parallels Desktop Configuration File
pwd     password (AIR FTP, AUTODESK)
pwd     Portable Word Document
pwl     Windows Password List
pwp     PhotoWorks Package
pxr     Pixar Image File
py     Python Script

Q-R -> A | B | C | D | E-F | G-H | I | J-L | M | N-O | P | Q-R | S | T-U | V | W | X-Z

File Extn MIME Type Start
q     JB2
qd3 x-world/x-3dmf   Data file - segment 3 (Omnis Quartz)
qd3d x-world/x-3dmf    
qif     Quicken Interchange format
qrt application/quest   Qrt ray tracing graphics
qt video/quicktime   QuickTime
qxd application/quarkxpress   QuarkXpress Document
qfx   Quicken Transfer Format
qxp application/quarkxpress   QuarkXpress Project
ra audio/x-realaudio   Music (RealAudio)
raf     digital camera - Fuji CCD-RAW Graphic File
ram audio/x-pn-realaudio, video/x-pn-realvideo   RealMedia Metafile
rar     WinRAR Compressed Archive (Roshal ARchive)
ras image/x-cmu-raster   Sun Raster Format (raster)
raw     animated picture or Raw Image File
rax audio/   RealAudio 10 - RealMedia Streaming File
rdf   Resource Description Framework - Meta about resources on the web. See web 3.0.
rfa   Revit Family File - 3D model - Autodesk
rft text/richtext, text/rtf, application/rtf, application/msword   DCA-RFT -Document Content Architecture, Revisable Form Text
rgb image/x-rgb   RGB Color Image
rib     RenderMan 3D data
rip     Quincy for Win32 - Abnormal Termination Report
rip image/rip   Graphics (Remote Access)
rle     Windows/OS/2 Bitmap (picture)
rm application/vnd.rn-realmedia
  Real Media
rmf     Rich Map Format - used in various 3-D games to store maps
rmf audio/x-rmf   Rich Music Format audio file from Beatnik
rmi audio/mid   MIDI File
rmvb application/vnd.rn-realmedia-vbr   RealVideo Variable Bit Rate FIle
rng application/ringing-tones
  Nokia Phone Ringtone File
roff application/x-troff   Troff
rol     sound
rpm audio/x-pn-realaudio-plugin   Real Audio Plugin and RedHat Package Manager
rrf application/x-InstallFromTheWeb    
rsrc     Mac Resource File
rss     Rich Site Summary or "Really Simple Syndication". A lightweight XML format designed for sharing news headlines.
rtc application/rtc    
rte     Magellan GPS Route file
rtf application/rtf   Rich Text Format (Microsoft)
rtttl text/richtext   Ring Tones Text Transfer Language File
rtx text/richtext   MIME Richtext format (see also rtf)
rtx     extended ringtone format - Mobil Phone
rtsp application/x-rtsp   QuickTime Real-Time Streaming Protocol File
rx     Hummingbird X Web Remote Activation

S -> A | B | C | D | E-F | G-H | I | J-L | M | N-O | P | Q-R | S | T-U | V | W | X-Z

s3m     sound
sam     Ami Pro
sav     SPSS Data File
sb application/x-xsb   Superbook
sbn     ArcView Spatial Index For Read-Write Shapefiles (GIS)
sbx application/x-xsb   ArcView Spatial Index For Read-Write Shapefiles
sca application/x-supercard   Datafile (SCA)
scm     ScreenCam
scp text/x-palm-scp   Palm Network Script File
scp text/x-palm-scp   Palm Network Script File
scr     Screen Font
scr     Screen Saver (executable)
scx     image
sdn     shell archive
sdp application/sdp   Scalable Multicast (RealNetworks)
sea     Self Extracting Archive
ser application/java-
ser     Metamail Server File
sf     IRCAM Sound
sgi     picture
sgl     SCODL
sgm text/x-sgml   Standard Generalized Markup Lang (SGML)
sgml text/x-sgml   Standard Generalized Markup Lang (SGML)
sh application/x-sh   SH Script
shar application/x-shar   Sh Shar
shg     image
shk     compressed (Mac)
shp     SRI GIS & Mapping Software Shape File - ArcView
shn     Shorten Audio Compression File
shx     ArcView DataBase Index
shtml magnus-internal/parsed-html    
shw application/presentations   Presentation (Harvard Graphics 2.0 - CorelShow)
sif     Windows NT Setup File
sig application/pgp-signature   Detached signature file (PGP)
silo model/mesh    
sit application/x-stuffit   StuffIt - Macintosh Compression Format. By Aladdin for Mac.
sitx application/x-stuffit   StuffIt X file format integrates compression with security and safety options. By Aladdin for Mac.
sithqx     StuffIt BinHex Archive
skd application/x-koan    
skm application/x-koan    
skp application/x-koan    
skr application/pgp-keys   Private Keyring (PGP)
skt application/x-koan    
sla     Scribus document (page layout)
slk     (.SYLK) Symbolic Link WingZ/Excel/Lotus (old MultiPlan form)
smi     Self Mounting Image file (Disk Copy Apple)
smil application/smil   SMIL Synchronized Multimedia Integration Language. App:RealPlayer
smf     Standard MIDI File
smf     OpenOffice.org Formula
sml application/smil   SMIL Synchronized Multimedia Integration Language
smp application/studiom   Sample (sound file)
snd audio/basic   8-bit u-law [PCM] / 8000 Hz Audio
snp application/vnd.ms-access   MS Access Snapshot
spc text/x-speech   SpchComp Encoded Speech/Audio
spc application/x-pkcs7-certificates   PKCS #7 Certificate
spc text/x-palm-spc   Palm Configuration File
spl application/futuresplash   FutureSplash from FutureWave Sftwr
spo   SPSS Statistical Output File
spr application/x-sprite   Document letter (Sprint)
sprite application/x-sprite    
spss   SPSS Script File
sql     Structured Query Lang
sqz     squeeze for MSDOS
src application/x-wais-source   WAIS Source
srv   BNBSURVEY Configuration File
stk application/hstu    
stm     Microsoft - Exchange Server Streaming Store
stm     The .stm extension tells an NT web server (Site Server 3.0) to look for #include directives.
stream audio/x-qt-stream    
stw     OpenOffice Template
sty application/msword   MS Word Style sheet
sum   Stata Checksum File
sup   Supplemental Data, Usually a form of user dictionary.
sv4cpio application/x-sv4cpio   SVR4 CPIO
sv4crc application/x-sv4crc   SVR4 CPIO w/CRC
svf image/vnd    
svg image/svg+xml   Scalable Vector Graphics
svh image/svh    
svr x-world/x-svr   Compressed Virtual World
swa application/x-shockwave-audio, application/x-director   Shockwave Audio
swf application/x-shockwave-flash
  Macromedia Flash Format File for animations
sxc     OpenOffice Spreadsheet
sxw     OpenOffice
syl application/sylk   SYLK - Symbolic Link WingZ/Excel/Lotus (old MultiPlan form
sys application/octet-stream   PC System File

T-U -> A | B | C | D | E-F | G-H | I | J-L | M | N-O | P | Q-R | S | T-U | V | W | X-Z

File Extn MIME Type Start
t application/x-troff   Troff
tab     Tab separated Text (usually .tsv)
talk application/talker, text/x-speech   Text to Speech
tar application/x-tar   4.3BSD Tar
targa image/targa   Targa Image File
taz     Unix Tar.Z Archive
tbk application/toolbook   Memo backup (dBASE IV - FoxPro)
tcl application/x-tcl   TCL Script
tda text/x-palm-tda   ToDo Archive (Palm)
tdo     compressed
tex application/x-tex   TeX Source
texi application/x-texinfo   Texinfo
texinfo application/x-texinfo   Texinfo
tga image/targa   Targa/Truevision Image File
tgz application/x-gzip   UNIX GTar Arvhive
tif image/tiff   TIFF - Tag Image File Format. Includes GeoTIFF (lossless storage format)
tiff image/tiff   TIFF - Tagged Image File Format
tlb     Type Library (SPSS, OLE, Visual C++)
tlk application/x-tlk    
tmv application/x-Parable-Thing   Template (TextMaker)
toc application/vnd.framemaker   FrameMaker TOC
tor     Lomax Software Info File
application/x-bittorrent   BitTorrent Metainfo File. Shareaza, BitComet
tpg     National Geographic TOPO! mapsmapXchange Document
tpo     National Geographic TOPO! mapsmapXchange Document
tpp     TOPO! reference file
tps     Temporary Postscript - FrameMaker
tr application/x-troff   Troff
trm application/x-msterminal   MS terminal
trn     TeleChart trendline file
trn     SQL Server Transaction Backup and others (Pagemaker, Quattro, ...).
ts     terminal settings (eXceed telnet)
tsi audio/tsplayer    
tsp application/dsptype   Windows Telephony Service Provider
tsv text/tab-separated-values   Tab Separated Values
tsz   TOPO! mapping software
ttf     TrueType Font
tx8     DOS Text
txt text/plain   Plain Text
txt application/wordperfect   WordPerfect 6-11
u98     Urdu 98 Document
u3p     U3 Smart Application for SanDisk U3 SmartDrive. zip format with .exe
uc2     UltraCompressor II compressed archive
UDF   Universal Disk Format - This is a file system coding standard for CD's and DVDs. I have never seen a file with this extension type.
udf   SQL User Defined Function Script file.
udf   Excel user defined function.
uin application/x-icq   ICQ 2001+ Saved ICQ Contact Information
ul     sound
um     uuencoded
upd     Universal Print Driver
upt     Magellan GPS WayPoint (POI) file
url application/x-url wwwserver/redirection application/internet-shortcut   Uniform resource Locator (Internet Address)
ustar application/x-ustar   IEEE Std1003.2 (``POSIX'') Tar
utl     sound
uu     uuencoded (7-bit)
uud     uudecoded
uue     uuencoded
V -> A | B | C | D | E-F | G-H | I | J-L | M | N-O | P | Q-R | S | T-U | V | W | X-Z
File Extn MIME Type Start
v5d application/vis5d   5-D data set visualization
vat     video audio tool
vbd application/activexdocument   ActiveX file
vcs text/x-vcalendar   Personal Data Interchange (PDI) Calendar entry - Outlook
vcd   VisualCAD Drawing file
vcd application/x-cdlink   VirtualDrive CD Image File
vcf text/x-vcard   vCard (Business Card)
vdo video/vdo   VDOLive Script Video image (Story Board)
vgm video/x-videogram    
vfd     Virtual Floppy Drive Image
vgp video/x-videogram-plugin    
vgx video/x-videogram    
vic     VICAR (Video Image Access and Retrieval) raster image
vis     Visual Importer Script
viv video/vnd.vivo   VivoActive Player Video file
vivo video/vnd.vivo    
vlc application/videolan   VLC Media Player Data.
vmd application/vocaltec-media-desc    
vmf application/vocaltec-media-file   Font characteristics (Ventura Publisher)
vnt text/x-vnote   Mobile Phone vNote File - QUOTED-PRINTABLE QP format
vob video/dvd, video/mpeg   DVD Video Movie File
voc     sound
vox audio/voxware   Vox Audio
vqe audio/x-twinvq-plugin   Yamaha Sound-VQ Locator file
vqf audio/x-twinvq   Yamaha Sound-VQ file
vql audio/x-twinvq   Yamaha Sound-VQ Locator file
vrml model/vrml   Virtual Reality Modeling Language  
vro     DVD Recorder File
vrt x-world/x-vrt    
vsd     Visio Drawing
vss     Visio Stencil
vst     Visio Template
vst     Photoshop Elements
vtp     VT420 profile (Rumba VT420 (SPRY Telnet) session profile
vts workbook/formulaone   Forumle One - A Java Spread sheet and report generator from Tidestone
vxd     Virtual Device Driver
W -> A | B | C | D | E-F | G-H | I | J-L | M | N-O | P | Q-R | S | T-U | V | W | X-Z
wab     Windows (Outlook) Address Book
waf plugin/wanimate   Mayim's WAF Compiler file for interactive 3D with Walkabout browser plug-in
waf     MS IE Web Archiv (on Mac)
wan plugin/wanimate    
wav audio/x-wav, audio/wav   Windows Audio File WAVE format
wax audio/x-ms-wax   Windows Media Audio Redirector to WMA file.
wb     white board
wb2     QuatroPro
wbmp image/vnd.wap.wbmp   Wireless Bitmap File Format - Mobil phones
webm   Compressed video file created using the WebM format, an open, high-quality video standard; stores video compressed using VP8 technology.
wi image/wavelet    
wid application/x-DemoShield   Width table (Ventura Publisher)
wis application/x-InstallShield    
wk1     Lotus 1-2-3 Worksheets
wks application/x-msworks   MS Works or Lotus 1-2-3 Worksheets
wkz     for Wingz spreadsheet from Informics
wlt application/x-mswallet   eWallet file
wm video/x-ms-wm    
wma audio/x-ms-wma   Windows Media Audio. Stored in ASF.
wme     Windows Media Encoder Session Profile
wmf image/x-wmf   Windows MetaFile vector graphics
wmf image/x-msmetafile   Windows MetaFile (metafile)
wml text/vnd.wap.wml   Wireless Markup Language File
wml text/wml   Website META Language File
wmv video/x-ms-wmv   Windows Media Video (Stored in ASF format). Use Windows Media Player on Windows and Flip4Mac WMV to play wich QuickTime on a Mac.
woff application/font-woff   Web Open Font Format File
wp application/wordperfect   WordPerfect
wpc application/wpc   Text-format converters used 1990-1997 by MS Word and Write
wpc application/pcms_wp   WordPerfect Character Mapping File
application/wordperfect5.1, application/wordperfect6, application/wordperfect8   Document (WordPerfect)
wpf     WordPerfect (variation is .WP)
wpg     WordPerfect Graphics (metafile)
wps application/vnd.ms-works
  MS Works
wpt     Magellan GPS WayPoint (POI) file
wri application/x-mswrite   Write format (MS Windows)
wrl     Cosmo Player VRML Worlds
wrl model/vrml, x-world/x-vrml   Plain Text VRML File
wrz x-world/x-vrml    
wsd     WordStar
wtx audio/x-wtx, audio/wtx    
wvx video/x-ms-wvx    
X-Z -> A | B | C | D | E-F | G-H | I | J-L | M | N-O | P | Q-R | S | T-U | V | W | X-Z
File Extn MIME Type Start
xbm image/x-xbitmap   X Bitmaps
xdr video/x-videogram    
xla application/vnd.ms-excel   MS Excel (Add in)
xlam application/vnd.ms-excel.
  MS Excel 2007 add-In
xlc application/vnd.ms-excel   MS Excel (Chart)
xlm application/vnd.ms-excel   MS Excel Macro
xlr MS Works
xls application/vnd.ms-excel \xD0CF
MS Excel
xlsm application/vnd.ms-excel.
  MS Excel 2007 XML macro-enabled Workbook
xlsx application/vnd.openxmlformats-
\X50 4B 03 04 MS Excel 2007 XML Workbook
xltx application/vnd.openxmlformats-
  MS Excel 2007 XML Template
xlt application/vnd.ms-excel   MS Excel (template)
xlw application/vnd.ms-excel   MS Excel (workbook)
xm     sound
xml text/xml   Extensible Markup Language
xpi application/x-xpinstall   Mozilla/Firefox Extension Archive
xpm image/x-xpixmap   X Pixmap format
xsb application/x-xsb   Superbook
xsl     Extensible Style Language
xtd   XML Type Definition
xul application/vnd.mozilla.xul+xml
  XML User Interface Language
xwd image/x-xwindowdump   X Window Dump (xwd)
xyz chemical/x-pdb   ASCII RPG Maker Graphic Format
xy     XyWrite
y     Amiga Yabba Compressed Archive
yuv     Color Space Pixel Format - (CCIR 601 4:1:1) Bitmap image
z application/x-compress, application/x-compressed   Compressed file ASCII archive created by COMPRESS
or Gzip
Z application/x-compress, application/x-compressed, application/gzip   UNIX Compressed Archive File
zdl application/x-zip-compressed, application/zip, application/x-compressed   PKZIP
zip   DesignPro Label Design, e.g Bus Cards, display sftwr at avery.com
zoo     compressed Zoo archive
zpa application/pcphoto    
zw     Chinese
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Start With - Identifying characters at the beginning of the file. \x = Hex Char.