Most Common file types and extensions

Common file extensions that are good to know, organized by file format.

Text Files
----------
.doc Microsoft Word Document
.docx Microsoft Word Open XML Document
.log Log File
.msg 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
.mdb Microsoft Access Database
.pps PowerPoint Slide Show
.ppt PowerPoint Presentation
.sdb OpenOffice.org Base Database File
.sql Structured Query Language Data
.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
.dxf Drawing Exchange Format File
.eps Encapsulated PostScript File
.ps PostScript File
.svg Scalable Vector Graphics File

3D Image Files
---------------
.3dm Rhino 3D Model
.3dmf QuickDraw 3D Metafile
.dwg AutoCAD Drawing Database File
.pln ArchiCAD Project File

Page Layout Files
------------------
.indd Adobe InDesign File
.pdf Portable Document Format File
.qxd QuarkXPress Document
.qxp QuarkXPress Project 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
.mkv Matroska Video File
.mov Apple QuickTime Movie
.mp4 MPEG-4 Video File
.mpg MPEG Video File
.qt Apple QuickTime Movie
.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
.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
.sea Self-Extracting Archive
.sit Stuffit Archive
.sitx Stuffit X Archive
.zip Zipped 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
-------------
.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