Common Filename Extensions last revised 12/17/99

(Notes: Some programs may use these extensions for other types of files, so we don't guarantee that this list will match how they're set up on your computer. This list is provided for general information only. Never delete a file unless you have a ready backup or are absolutely sure what it is. Also, there are many other types of files that are not listed here; this is just a sample list of some of the most common extensions. Remember, the extension doesn't really have anything to do with how the file is formatted - it just tells Windows what program to use when attempting to open the file.)


??_ = LZW Compressed file for use with Expand command

??K = Usually, if an extension ends with K, it is a backup file for a particular program (except BMK--Help Bookmark)

??T = Possibly a Template file for the format that starts with the same two letters

3GR = Enhanced mode video grabber

ACL = MS Office AutoCorrect list

ACM = Microsoft Setup file

ACP = MS Office Assistant Character Profile (Actor)

ACT = MS Office Assistant Character Actor file

ADI = AutoCAD plotter file

AFM = Adobe Font Metrics

AI = Adobe Illustrator drawing

ANI = Animated cursor

ANN = Help annotation file

AVI = Audio/Video Interleave (MS Movie), video clip

BAK = Backup files

BAS = Basic program. Requires the proper version of Basic language to run

BAT = Batch file of executable DOS commands

BIN = Binary file (usually a program supplement)

BMK = Help file added bookmark file

BMP = bitmaps (Paintbrush picture)

CAB = Cabinet files (compressed files for use by an installation program)

CAL = Calendar file

CBT = Computer Based Training (tutorial)

CCH = CorelChart

CDR = CorelDraw drawing

CDT = CorelDraw template

CFG = Program configuration file

CGM = Computer Graphics Metafile (vector graphics)

CLB = Corel Draw compressed drawing library

CMP = lossy bitmap compression format

CMX = Corel Presentation Exchange

CNT = Windows 95 Help Contents file

CNV = File format converter file

COM = Executable DOS commands or programs

CPE = Cover Page Editor document (Microsoft Fax)

CPL = Control Panel Library (contains code for Control Panel functions)

CPS = Central Point Virus Checker tracking file

CPT = Corel Photopaint bitmap

CRD = Cardfile card stack file

CUR = Cursor

DA0 = Registration backup file

DAT = Program data file

DBF = Database file (originally Dbase, but used by many programs)

DES = Database description file (ACT!)

DIB = Windows Device Independent Bitmap

DIC = Custom dictionary

DIR = ??

DIZ = ??

DLL = Dynamic Link Library, program module that can be called by any executable

DOC = Documents (usually Microsoft Word for Windows)

DOT = Document template (usually Microsoft Word for Windows)

DRV = Device drivers

DTB = Uninstaller smartlinks file

DXF = AutoCAD drawing

EPS = Encapsulated Postscript drawing file

EXE = Executable program (application)

FEN = ??

FIF = Font information file??

FLI = Animation file

FLT = Graphics import/export filter

FON = Bitmap? Font

FOT = TrueType Font reference file (also requires a .TTF file)

FRM = Form definition

FTS = Win95 Help Index file (allows word search within Help file)

FTG = Win95 Help Index file

GED = ?? GEDCOM family tree information

GID = Windows 95 Help setup info file. Created first time you use the file. Modified when you access Help.

GIF = Graphics Image Format (CompuServe) bitmap

GLB = Global? Mail files (give info about programs)??

GRB = Grabber file (usually for Windows to interface with hardware)

GRP = Program Manager Application group (defines which icons are in which window)

HGL = Hewlett Packard Graphics Language

HLP = Windows help files

HTM = Hyper text markup language (web page)

ICC = Windows 95 color management profile

ICL = Icon library

ICO = Icon file (note: many .exe and .dll files also contain icons)

IDB = Quicken Inventory Database

IDF = MIDI Instrument Definition

IDX = Index file

IIF = QuickBooks for Windows export file

INF = Setup information

INI = Windows initiation files (information the system uses at program startup; user settings)

JFF = JPEG bitmap

JPG = JPEG (Joint Photographic Experts Group) lossy bitmap compression format

LDB = MS Access library file

LEX = Dictionary or thesaurus file

LIB = Library file

LNK = Win95 shortcut

LOG = Log

LZW = Lempel-Ziv-Welch, lossless bitmap compression format

MDA = MS Access Database Wizard or Template

MDB = MS Access database

MDW = MS Access workgroup information

MDX = ??

MID = MIDI (Musical instrument digital interface) sound file

MIX = MS PhotoDraw graphic metafile

MMM = Multiple Master metrics (Adobe)

MPC = MS Project calendar

MPG = MPEG compressed video

MPP = MS Project project file

MPT = MS Project template

MSM = Microsoft Mail ?? file

MVB = Multimedia Viewer (book?) file

OLD = Copy of configuration file made during program installation

OSS = MS office saved search

PAB = Win95 Personal Address Book

PAL = Color pallette

PAR = Windows Swap File

PAT = Bitmap pattern for filling drawing objects

PCD = Kodak Photo CD bitmap

PCL = Printer Control Language file

PCS = Microsoft Office Clipart Gallery

PCX = PC Paintbrush bitmap

PFB = Printer Font binary (Adobe)

PFM = Printer Font Metrics (Adobe)

PIC = Lotus graphics

PIF = Program Information File (tells Windows how to run DOS apps)

PLT = HP plotter print file

PPT = Powerpoint slide show

POT = Powerpoint 95 presentation template

PRN = Printer file

PSD = Adobe PhotoShop image

PST = MS Exchange (Outlook) profile

PWL = Password Library file

QBB = QuickBooks for Windows backup file

QBW = QuickBooks for Windows file

REC = Recorder macro file

REG = Registration information

REP = Report template (ACT!)

RLE = Run Length Encoding, lossless bitmap/video compression format.

RMI = Some kind of media player music file (similar to MIDI)

RTF = Rich Text Format

SAM = Ami Pro document

SCD = Microsoft Schedule+ calendar file

SCR = Screen saver

SET = MS Backup settings file

SHD = Printer spooling file

SPL = Printer spooling file

STF = Setup file??

SWP = Swap file

SYD = Backup configuration files created by using SYSEDIT

SYS = either text system files (like CONFIG.SYS) or system drivers

TAX = Tax program file

TGA = Targa bitmap

TIF = Tagged image file format (TIFF) bitmap format for scanned images and photos

TMP = temporary files. TMPs that start with ~ are Windows temp files

TPL = Template file (ACT!)

TRM = Windows Terminal settings

TRN = Translator

TTF = True Type font (note: also requires .FOT file)

TUT = Tutorial file

TXT = Text files (ASCII characters)

UDL = Uninstaller backup file

VBX = Visual Basic program??

VIR = Norton Antivirus backup file

VSD = Visio drawing

VSS = Visio stencil

VXD = Virtual device driver

WAV = Wave digital audio sound file

WDB = MS Works database

WK* = Lotus 123 worksheet files

WKS = MS Works spreadsheet

WLL = MS Word Link Library

WMF = Windows Metafile (vector graphics - clipboard format

WPC = (something to do with 32bit versions, mswrite32.wpc, msword_632.wpc, etc.)

WPD = Word Perfect Document (also used by ACT)

WPS = MS Works document

WRI = Microsoft Windows Write documents

XLA = Microsoft Excel for Windows add-in macro sheet

XLB = Microsoft Excel for Windows settings

XLM = Microsoft Excel for Windows macro sheet

XLS = Microsoft Excel for Windows worksheets (spreadsheets)

XLT = Microsoft Excel for Windows templates

*.386 =

ZIP = PKZip compressed file

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