Common file extensions

Text Files

.doc	Microsoft Word Document
.docx	Microsoft Word Open XML Document
.log	Log File
.msg	Outlook Mail Message
.pages	Pages Document
.rtf	Rich Text Format File
.txt	Plain Text File
.wpd	WordPerfect Document
.wps	Microsoft Works Word Processor Document

Data Files

.123	Lotus 1-2-3 Spreadsheet
.accdb	Access 2007 Database File
.csv	Comma Separated Values File
.dat	Data File
.db	Database File
.dll	Dynamic Link Library
.efx	eFax Document
.mdb	Microsoft Access Database
.pps	PowerPoint Slide Show
.ppt	PowerPoint Presentation
.pptx	Microsoft PowerPoint Open XML Document
.sdb	OpenOffice.org Base Database File
.sdf	Standard Data File
.sql	Structured Query Language Data
.uccapilog	Microsoft UCC API Log File
.vcf	vCard File
.wks	Microsoft Works Spreadsheet
.xls	Microsoft Excel Spreadsheet
.xlsx	Microsoft Excel Open XML Document
.xml	XML File

Image Files

.pct	Picture File

Raster Image Files

.bmp	Bitmap Image File
.gif	Graphical Interchange Format File
.jpg	JPEG Image File
.png	Portable Network Graphic
.psd	Photoshop Document
.psp	Paint Shop Pro Image File
.thm	Thumbnail Image File
.tif	Tagged Image File

Vector Image Files

.ai	Adobe Illustrator File
.drw	Drawing File
.eps	Encapsulated PostScript File
.ps	PostScript File
.svg	Scalable Vector Graphics File

3D Image Files

.3dm	Rhino 3D Model
.dwg	AutoCAD Drawing Database File
.dxf	Drawing Exchange Format File
.pln	ArchiCAD Project File

Page Layout Files

.indd	Adobe InDesign File
.pdf	Portable Document Format File
.qxd	QuarkXPress Document
.qxp	QuarkXPress Project File
.rels	Open Office XML Relationships File

Audio Files

.aac	Advanced Audio Coding File
.aif	Audio Interchange File Format
.iff	Interchange File Format
.m3u	Media Playlist File
.mid	MIDI File
.midi	MIDI File
.mp3	MP3 Audio File
.mpa	MPEG-2 Audio File
.ra	Real Audio File
.wav	WAVE Audio File
.wma	Windows Media Audio File

Video Files

.3g2	3GPP2 Multimedia File
.3gp	3GPP Multimedia File
.asf	Advanced Systems Format File
.asx	Microsoft ASF Redirector File
.avi	Audio Video Interleave File
.flv	Flash Video File
.mov	Apple QuickTime Movie
.mp4	MPEG-4 Video File
.mpg	MPEG Video File
.rm	Real Media File
.swf	Flash Movie
.vob	DVD Video Object File
.wmv	Windows Media Video File

Web Files

.asp	Active Server Page
.css	Cascading Style Sheet
.htm	Hypertext Markup Language File
.html	Hypertext Markup Language File
.js	JavaScript File
.jsp	Java Server Page
.php	Hypertext Preprocessor File
.rss	Rich Site Summary
.tvpi	TitanTV Television Listing File
.tvvi	TitanTV Television Listing File
.xhtml	Extensible Hypertext Markup Language File

Font Files

.fnt	Windows Font File
.fon	Generic Font File
.otf	OpenType Font
.ttf	TrueType Font

Plugin Files

.8bi	Photoshop Plug-in
.plugin	Mac OS X Plug-in
.xll	Excel Add-In File

System Files

.cab	Windows Cabinet File
.cpl	Windows Control Panel
.cur	Windows Cursor
.dmp	Windows Memory Dump
.drv	Device Driver
.key	Security Key
.lnk	File Shortcut
.sys	Windows System File

Settings Files

.cfg	Configuration File
.ini	Windows Initialization File
.prf	Outlook Profile File

Executable Files

.app	Mac OS X Application
.bat	DOS Batch File
.cgi	Common Gateway Interface Script
.com	DOS Command File
.exe	Windows Executable File
.pif	Program Information File
.vb	VBScript File
.ws	Windows Script

Compressed Files

.7z	7-Zip Compressed File
.deb	Debian Software Package
.gz	Gnu Zipped File
.pkg	Mac OS X Installer Package
.rar	WinRAR Compressed Archive
.sit	Stuffit Archive
.sitx	Stuffit X Archive
.zip	Zipped File
.zipx	Extended Zip File

Encoded Files

.bin	Macbinary II Encoded File
.hqx	BinHex 4.0 Encoded File
.mim	Multi-Purpose Internet Mail Message
.uue	Uuencoded File

Developer Files

.c	C/C++ Source Code File
.cpp	C++ Source Code File
.java	Java Source Code File
.pl	Perl Script

Backup Files

.asd	Microsoft Word AutoSave File
.bak	Backup File
.bup	Backup File
.gho	Norton Ghost Backup File
.ori	Original File
.tmp	Temporary File

Disk Files

.dmg	Mac OS X Disk Image
.iso	Disc Image File
.toast	Toast Disc Image
.vcd	Virtual CD

Game Files

.gam	Saved Game File
.nes	Nintendo (NES) ROM File
.rom	N64 Game ROM File
.sav	Saved Game

Misc Files

.msi	Windows Installer Package
.part	Partially Downloaded File
.torrent	BitTorrent File
.yps	Yahoo! Messenger Data File