Most Popular File Extension Types
_IPOD_CONTROL - _IPOD_CONTROL is a hidden iPod001 - Represents one of several files in a series
1 - One of a series
2 - IBM Voice Type Language Script Data
3G2 - 3rd Generation Partnership Project 2 (3GPP2) Multimedia
3GP - 3GPP Multimedia
7Z - 7 - ZIP File Compression files
ABM - Album files
AIR - Flight Simulator Aircraft Performance Info File / AIR Rich Internet Application
AMSORM - Auction Client
API - Acrobat Plug - in
AS4 - AS / 400 Client Access files / SurfSaver Files
ASP - Active Server Page
ASPX - Active Server Page Extended
BAK - Backup files
BIN - Binary
BOOT - InstallShield Boot
BUP - Backup files
BZ2 - BZip2 Compressed
CACHE - Cache
CFG - CFG or .cfg
CHK - Saved File Fragment
CLASS - Java Class File
COD - Compiled Source Code
CSV - Comma Separated Values
CWK - ClarisWorks Document
DAA - PowerISO Direct - Access-Archive
DAP - Access Data Access Page / Download Accelerator Temporary File During Download
DAT - Data
DATA - Font2D Resources file
DB - Database files
DBF - Database
DEB - Debian Software Package
DIVX - DivX - Encoded Movie
DJVU - DJVU (pronounced “Déjà vu”)
DLL - Dynamic Link Library
DMG - Macintosh OS X Disk Copy Disk Image
DMP - Screen or Windows Memory Dump
DO - Java Servlet
DOC - Word Document
DOCX - Microsoft Word 2007 Document
DOT - Microsoft Word Template
EX_ - Compressed .exe
FLV - Flash Video
FX - DirectX D3DXEffect Object / WordPerfect Office Template
FXP - FoxPro Compiled Source
GADGET - Microsoft Gadget
GBA - Nintendo Game Boy Advance ROM Image
GED - Genealogy
GP3 - CCITT Group 3 File / Guitar Pro
GZ - Gzip Compressed Archive
HMT - HighMat
HQX - BinHex 4.0 Encoded
HT_ - Hot Potatoes Source
ICA - Image Object Content Architecture (IOCA) file and also Citrix ICA
ICO - Windows Icon
ID - Lotus Notes ID
IDX - Index Files
IFO - DVD Information Files
IN_ - Setup information file or compressed file that’s part of an installation
INX - InstallShield Compiled Rules File and Adobe InDesign Interchange format
IPD - Blackberry Backup
ITHMB - iPod Photo Thumbnails
ITL - iTunes Library
JAR - Java Archive
JBF - Paint Shop Pro Browser Cache / Backup Now Backed Up
JBK - Juno Backup Files
JNLP - Java Network Launching Protocol
JP2 - JPEG 2000 Core Image
JSP - Java Server Page
KML - Keyhole Markup Language
KMZ - Google Earth Saved Working Session / Placemark
LIST - BlindWrite
LOC - EasyGPS TerraByte Location
LWTP - LimeWire Theme Pack
M4A - MPEG - 4 Audio Layer
M4P - MPEG - 4 Video
M4V - MPEG - 4 Video
MANIFEST - Windows Visual Styles
MB - MapBasic Program
MBB - ManaBook
MDB - Microsoft Access Database
MDI - Microsoft Document Imaging
ME - Formatted Manual Page using ME Macros
METADATA_NEVER_INDEX - An instruction that restricts a particular folder or directory from being indexed
MOD - Module File - Various programs use this extension including: Amiga Music Module File (this is the most common use) / ArchiCAD Module / Fortran Module File /JVC Recorded Video File / CADdy++ Mechanical 2D/3D Model Data / CATIA Export
MOV - QuickTime Video Clip
MP3 - Audio files
MP4 - MPEG - 4 Video
MPG - MPEG Video
MSG - E - mail message
MSO - Word OLE Web Page Storage Stream
MST - Windows SDK Setup Transform Script
MUI - MultiLanguage Resource
NES - Nintendo Entertainment System ROM Image
OCX - Object Linking and Embedding (OLE) Control Extension also known as ActiveX control
ODS - Outlook Express 5 Mailbox / OpenDocument Spreadsheet
ODT - OpenOffice and StarOffice OpenDocument Text Document
OFX - Open Financial Exchange
OGG - Ogg Vorbis Codec Compressed Multimedia
ORIG - A file that has been renamed to indicate that it is an original file.
P7M - Compressed files
PACKAGE - Linux Autopackage File or the Sims 2 Package
PAF - Personal Ancestral File Family Database / Portable Application Installer
PANDO - Pando Package
PART - Partial download
PBP - PSP Firmware Image
PDF - Adobe Portable Document Format
PES - Embrid Embroidery Format
PF - Private Files
PGM - Portable Graymap Graphic
PHP - PHP Script
PIP - Office Personalized Menu and Toolbar
PKG - Mac OS X Installer Package / Symbian Installer Package
PLAYLIST - Cyberlink DVD Player Playlist
PLS - Playlist
PPD - PostScript Printer Description
PPS - PowerPoint Slideshow
PPT - PowerPoint Presentation
PRC - Palm OS Resource File / Corel Presentation
PROPS - Properties
PROTECTED - Protected files
PS - Post Script
PSD - Photoshop
PSF - ChiWriter PostScript Printer Font / Photoshop Proof Setup
PTB - Peachtree Complete Accounting Backup Data
PUB - Microsoft Publisher
QBB - QuickBooks Backup
QCP - Qualcomm PureVoice Audio
QFX - Quicken Financial Exchange
QIF - Quicken Interchange Files
QTL - QuickTime Media Link
RAM - Real Audio Media
RAR - WinRAR Compressed Archive
RMVB - RealVideo Variable Bit Rate
RPM - RealMedia Player Plug - in / also used for Red Hat Package Manager
RTF - Rich Text Format
SAV - Saved file or saved game
SDK - Auto Sketch Drawing
SH - UNIX / LINUX Shell Script
SIG - Most commonly represents either a signature file or a Broderbund sign file though other programs use the .sig file extension for a variety of other uses.
SIS - Symbian OS Installer
SIT - Stuffit Archive
SMC - Super Nintendo Entertainment System Game - console ROM Image
SOL - Flash MX SharedObject
SQM - Service Quality Monitoring File / Windows Live Messenger Log
STB - AutoCAD Plot Style Table
SWF - Flash Format
SYS - System files
TAR - Tape Archive Files
THM - Thumbnail files
TMP - Temporary File or Folder
TORRENT - BitTorrent Metainfo
UIF - MagicISO Universal Image Format
UNKNOWN - An unknown file extension
VOB - DVD Video Movie
W02 - Part of a compressed archive
WBZ - WebShots Image
WIDGET - Yahoo! Widget
WK4 - Lotus 4 Worksheet
WMV - Windows Media
WPD - 602PC SUITE Document File or Act! Word Processor
WPL - Windows Media Player Playlist
WPS - Microsoft Works Document
XDS - Symantec Store Download Manager Partial Download
XFDL - Extensible Forms Description Language
XLS - Microsoft Excel Spreadsheet
XPI - Mozilla Installer Package
Z - Unix Compressed
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