What Is a Filing Extension?

Windows system files are divided into many types according to different formats and uses. To facilitate management and identification, when naming files, they are distinguished by extensions, that is, the file name format is: "main file name. Extension". In this way, you can determine the type of file based on the file extension, and know its format and use.

Common file extensions

ISO:

A Common file extensions beginning with A

Extension description

A: Object code library file

AAM: Authorware shocked file

AAS: Authorware shocked package

ABF: Adobe Binary Screen Font

ABK: CorelDRAW Automatic Backup File

ABS: This type of file is sometimes used to indicate an abstract (just like an abstract or synopsis in a scientific article, taken from abstract)

ACE: Ace Compressed File Format

ACM: Windows System Catalog File

ACP: Microsoft Office Assistant Preview File

ACT: Microsoft office assistant file

AD: After Dark Screen Saver

ADA: Ada source file (non-GNAT)

ADB: Ada source file body (GNAT); HP100LX organizer's contract database

ADF: Amiga Disk File

ADI: AutoCAD Device Independent Binary Plotter Format

ADM: After Dark multi-module screen saver; Windows NT policy template

ADP: FaxWork interactive installation file for fax modem; Astound Dynamite file

ADR: After Dark random screen saver; Smart Address's address book

ADS: Ada Source File Specification (GNAT)

AFM: Adobe's Font Scale

AF2 / AF3: ABC's FlowChat file

AI: Adobe Illustrator format graphics

AIF / AIFF: Audio Interchange File, Sound Format for Silicon Graphic and Macintosh Applications

AIFC: Compressed AIF

AIM: AOL Instant Messaging

AIS: ACDSee graphic sequence file; Velvet Studio equipment file

AKW: All A-keywords in RoboHELP's help project

ALB: JASC Image Commander Photo Album

ALL: Art and Letters Library

AMS: Velvet Studio Music Module (MOD) file; Extreme Tracker module file

ANC: Canon Computer's palette file containing a series of optional color palettes

ANI: Animated Cursor in Windows

ANS: ANSI text file

ANT: Game files saved in SimAnt For Windows

API: Application design interface file used by Adobe Acrobat

APS: Microsoft Visual C ++ file

APK: Android installation package

ARI: Aristotle Sound File

ARJ: Robert Jung ARJ archive file

ART: Xara Studio painting files; Canon Crayola art files; Clip Art file format; another ray tracing format; marker files compressed by Johnson-Grace compression algorithm used by AOL

ASA: Microsoft Visual InterDev file

ASC: ASC text file; PGP algorithm encrypted file

ASD: Auto-save file of Microsoft Word; description file of Microsoft advanced streaming format (ASF); Velvet Studio example file can be opened with NSREX

ASE: Velvet Studio Sample File

ASF: Microsoft Advanced Streaming Format File

ASM: assembly language source files, Pro / E assembly files

ASO: Astound Dynamite Object File

ASP: dynamic web file; ProComm Plus installation and connection script file; Astound introduction file

ASV: DataCAD automatically saves files

ASX: Cheyenne backup script file; Microsoft Advanced Streaming Redirector file, video file

ATW: Any Time Deluxe For Windows Personal Information Administrator File from Personal Software

AU: Sun / NeXT / DEC / UNIX sound file; audio U-Law (read as "mu-law") file format

AVB: Computer Associates Inoculan Anti-Virus Virus File

AVI: Microsoft Audio Video Interleave movie format

AVR: Audio Visual Research File Format

AVS: Application Visualization Format

AWD: FaxVien Document

AWR: Telsis Digital Storage Audio File Extension Format

Axx: Sub-package serial number file of ARJ compressed file, used to compress a large file into several small compressed packages (xx takes the number 01-99)

A3M / A4M: Authorware Macintosh Unpacked File

A4P: Authorware Runtime-Free Packaged File

A3W / A4W / A5W: Unpackaged Authorware Windows File

B Common file extensions beginning with B

Extension description

BAK: backup file

BAS: BASIC source file

BAT: batch file

BDF: West Point Bridger Designer file

BGL: Microsoft Flight Simulator Vision File

BI: binary files

BIF: Group Wise initialization file

BIFF XLIFE 3D format file

BIN binary

BK / BK $ is sometimes used to represent backup versions

BKS IBM BookManager Read Bookshelf File

BMK bookmark file

BMP Windows or OS / 2 bitmap file

BOOK Adobe FrameMaker Book file

BRX for viewing files in a multimedia object directory

BSP Quake Graphics File

Batch files used by the BTM Norton application

BUD Quicken backup disk

BUN CakeWalk sound bundle file (a MIDI program)

BW SGI black and white image file

BWV Commercial Wave File

C Common file extensions starting with C

Extension description

CC code file

CAB Microsoft Compressed File

Drafix CAD files for CAD Softdek

CAL CALS compressed bitmap; calendar schedule data

CAP compressed music file format

CAS comma separated ASC file

CB Microsoft Clean Boot File

CC Visual dBASE user-defined class file

CCB Visual Basic Dynamic Button Configuration File

CCH Corel chart file

CCO CyberChat Data File

CCT Macromedia Director Shockwave Projection

CDA CD audio track

CDF Microsoft Channel Definition Format File

CDI Philip's high-density disk interactive format

CDM Visual dBASE Custom Data Module File

CDR CorelDRAW drawing file; raw audio CD data file

CDT CorelDRAW template

CDX CorelDRAW compressed drawing file; Microsoft Visual FoxPro index file

CFG configuration file

CGI common gateway interface script file

CGM computer graphics metafile

CHK File fragmentation saved by Windows Disk Defragmenter or ScanDisk

CHM compiled HTML file

CHR character set (font file)

CIF Adaptec CD Creator CD image file

CIL Clip Gallery download package

CLASS Java class file

CLL Crick Software Clicker file

CLP Windows Clipboard File

CLS Visual Basic Class File

CMF Corel Metafile

CMV Corel Move Animation File

CMX Corel Presentation Exchange image

CNF Telnet, Windows and other configuration files used by applications whose format changes

CNM Windows application menu options and installation files

CNT Windows (or other) system used to help index or other purpose content files

COD Microsoft C compiler displayable machine code / assembly code file with source C code as a comment

COM command file (program)

CPL Control Panel Extension, Corel Color Plate

CPO Corel print storage file

CPP C ++ code file

CPR Corel provides instruction file

CPT Corel Photos-Painting Images

CPX Corel Presentation Exchange

CRD Windows Cardfile

CRP Corel runtime introduction file; Visual dBASE custom report file

CRT Certification Document

CSC Corel script file

CSP PC Emcee On_Screen image

CST Macromedia Director Cast file

CSV comma-separated value file

CTL is usually used to represent a file containing control information; it is used by FaxWork to hold information about each fax received or sent

CUR Windows cursor file

CV Corel version archive; Microsoft CodeView info screen file

CXX C ++ source code files

D Common file extensions beginning with D

Extension description

DAT data files; WrodPerfect merged data files; for some MPEG format files

DB Borland's Paradox 7 table

DBC Microsoft Visual FoxPro Database Container File

DBF dBASE file

DBX DataBearn image; Microsoft Visual FoxPro form file

DCM DCM module format file

DCS Desktop Color Delimited File

DCT Microsoft Visual FoxPro Database Container

DCU Delphi compilation unit file

DCX Microsoft Visual FoxPro database container; PCX-based fax image; macro

DEM file used to represent the USGS datum of the digital height model

DER certification

DEWF Macintosh Sound Cap / Sound Edit recording device format

DIB device independent bitmap

DIC Catalog

DIF data interchangeable spreadsheet

DIG DigiLink format; Sound Designer audio file

DIR Macromedia Director file

DIZ description file

DLG C ++ dialog script file

DLL dynamic link library

DLS downloadable sound files

DMD Visual dBASE Data Module File

DMF X-Trakker Music Module (MOD) File

DOC Word document

DOT Microsoft Word document template

DRAW Acorn object-based vector image file

DRV driver

DRW Micrografx Designer / Draw; Pro / E drawing file

DSF Micrografx Designer VFX file

File saved by DSG DOOM

DSM Dynamic Studio Music Module (MOD) File

DSP Microsoft Developer Studio project file

DSQ Corel QUERY (Query) File

DSW Microsoft Developer Studio workspace file

DTD SGML Document Type Definition (DTD) file

DUN Microsoft dial-up network export file

DV Digital Video File (MIME)

DXF interchangeable drawing file format, binary DWG format text representation; data exchange file

DXR Macromedia Director protected (non-editable) movie files

E Common file extensions beginning with E

Extension description

EDA Ensoniq ASR Disk Image

EDD element definition document (FrameMaker + SGML document)

EMD ABT Expansion Module

EMF Windows Enhanced Metafile

EML Microsoft Outlook Express Mail Message (MIME RFC822) File

EPHTML Perl explains enhanced HTML files

EPS compressed PostScript image

EXE executable file (program)

F Common file extensions beginning with F

Extension description

FAV Microsoft Outlook Navigation Bar

FAX fax type image

FCD Virtual CD-ROM

FDF A dobe Acrobat form document file

FFA / FFL / FFO / FFK Microsoft Quick Find File

FIF Fractal image file

FLA Macromedia Flash Movie

FLC Autodesk FLIC Animation File

PLI Autodesk FLIC Animation

FM Adobe FrameMaker Document

FML file mirror list (GetRight)

FNG font set file (Font Navigator, Font Navigator)

FNK Funk Tracker module format

FON system font

FOT font related files

FRT Microsoft FoxPro report file

FRX Visual Basic form text; Microsoft FoxPro report file

FTG full text search group file, generated by the Windows help system when looking for it-can be deleted and rebuilt if needed

FTS full text search citation file, generated by Windows help system when finding

G Common file extensions beginning with G

Extension description

GAL Corel Multimedia Manager Photo Gallery

GDB InterBase Database File

GDM Ringtone, Whistle, and Soundboard Module Format

GEM GEM metafile

Text files generated by GEN Ventura

GetRight GetRight Unfinished Download File

GFI / GFX Genigraphics graphic link presentation file

GHO Norton clone disk image

GIF CompuServe bitmap file

GIM / GIX Genigraphics graphic link presentation file

GKH Ensoniq EPS Family Cluster Disk Image File

GKS Gravis Grip Key Document

GL animation format

GNA Genigraphics graphic link presentation file

GNT generated code, executable code in Micro Focus attribute format

GNX Genigraphics graphics link presentation file

GRA Microsoft Graph file

GRF Grapher (Golden Software) graph file

GRP Program Management Group

GO Go language source files

H Common file extensions beginning with H

Extension description

HCOM sound tool HCOM format

HGL HP Graphics Language Drawing File

HLP help files; Date CAD Windows help files

HPJ Visual Basic Help Engineering

HPP C ++ program header files

HST history file

HT HyperTerminal

HTM / HTML Hypertext Document

HTT Microsoft Hypertext Template

HTX Extended HTML Template

I Common file extensions beginning with I

Extension description

ICB Targa bitmap file

ICC Kodak Printer Format File

ICL Icon Library File

ICM graphic color matching profile

ICO Windows icon

IDD MIDI device definition

IDF MIDI device definition (files required by Windows 95)

IDQ Internet Data Query File

IDX Microsoft FoxPro related database index file; Symantec Q & A related database index file; Microsoft Outlook Express file

IFF interchange format file; Amiga ILBM

IGES Initial Graphics Exchange Documentation

IGF insert system metafile

ILBM bitmap graphic file

IMA WinImage Disk Image File

INF information file

INI initialization file

INRS INRS telecommunications audio

INS InstallShield installation script

INT intermediate code, when a source program is compiled and checked to produce an executable code

IQY Microsoft Internet Query File

ISO lists files on CD-ROM according to ISD 9660 standard for CD-ROM file system

IST Digital Tracking Device File

ISU InstallShield uninstall script

IWC Install Watch document

J Common file extensions beginning with J

Extension description

J62 Ricoh Camera Format

JAR Java Archive

JAVA Java source files

JBF Paint Shop Pro image browsing file

JFF / JFIF / JIF JPEG files

JMPDiscovery Form Statistics File for JMP SAS

JPE / JPEG / JPG JPEG graphic file

JS Javascript source file

JSP HTML page with a reference to a Java servlet

JTF JPEG bitmap file

K Common file extension K

Extension description

K25 Kurzweil 2500 Sample File

KAR karaoke MIDI files

KDC Kodak light booster

KEY DataCAD icon toolbar file

KFX KoFak Group 4 image file

KIZ Kodak Digital Postcard File

KKW RoboHELP helps the engineering index designer to start with all keywords that have nothing to do with K

KMP Korg Trinity KeyMap file

KQP Konica Camera Local File

L Common file extensions beginning with L

Extension description

LAB Visual dBASE tag file

LBM Deluxe Paint bitmap file

LBT / LBX Microsoft FoxPro tag file

LDB Microsoft Access Lock File

LDL Corel Paradox distribution library

LEG Legacy documentation

LFT 3D Studio (DOS) Stakeout File

Logo file for LGO Paintbrush (Microsoft Paint Application)

LHA LZH Replace File Suffix

LIB library file

LIN DataCAD linear file

Output file from LIS Structured Query Report (SQR) program

LLX Laplink Exchange Agent

LNK Windows Shortcut File

LOG log file

LST list file

LU ThoughtWing library unit file

LYR DataCAD layer file

LZH LH ARC Compressed File

LZS Skyroads data file

M Common file extension M

Extension description

M1V MPEG related files (

M3U MPEG URL (MIME sound file)

MAD Microsoft Access module file

MAF Microsoft Access form file

MAM Microsoft Access Macro

MAP mapping files; Duke Nukem 3D WAD game files

MAQ Microsoft Access query file

MAR Microsoft Access report file

MAT Microsoft Access table; 3D Studio MAX material library

MB1 Apogee Monster Bash Data File

MBX Microsoft Outlook saves email format; Eudora mailbox

MCR DataCAD keyboard macro file

MDB Microsoft Access database

MDE Microsoft Access MDE file

MDL Digital Tracker Music Module (MOD) file; Quake module file

MDN Microsoft Access empty database template

MDW Microsoft Access Workgroup File

MDZ Microsoft Access Wizard Template File

MIC Microsoft Image Composer file

MID MIDI Music

MIM, MIME, MME Internet mail extension format multi-purpose file, often as a file created in AOL attachment when sending e-mail; files in a multi-zone MIM file can be opened with WinZip or other similar programs

MLI 3D Studio Material Library Format File

MNG multi-image network graphics

MNU Visual dBASE menu file; Intertel Systems Interact menu file

MOD Fast Tracker, Star Trekker, Noise Tracker (and more) music module files; Microsoft multi-plan spreadsheets; Amiga / PC track files

MOV QuickTime for Windows Movie

MP2 Layer 2 MPEG Audio File

MP3 Layer 3 MPEG Audio File

MPA MPEG related files, MIME "mpeg type"

MPE / MPEG / MPG MPEG animation file

MPP Microsoft project file; CAD drawing file format

MPR Microsoft FoxPro menu (compiled)

MSG Microsoft Mail Message

MSI Windows installation package

MSN Microsoft Web Documentation; Descent Mission File

MSP Microsoft Paint (paint) bitmap file; Windows Installer path file

Files with MST Windows Installer

MTM Multi Tracker Music Module (MOD) file

N Common file extensions beginning with N

Extension description

NAN Nanoscope file (Raw Grayscale)

NAP NAP Metafile

NCB Microsoft Developer Studio file

NCD Norton changes directory

NCF NetWare command file; Lotus Notes internal clipboard

NFF neutral file format

NFT NetObject Fusion template file

NIL Norton cursor library file (EasyIcons-compatible)

NIST NIST Sphere Sound

NLS national language support files for localization (for example, Uniscape)

NLU Norton Live Update e-mail trigger file

NTX CA-Clipper Index File

NWC Noteworthy Composer Song File

NWS Microsoft Outlook Express News

O Common file extensions beginning with O

Extension description

OBJ object file

OCX Microsoft Object Linking and Embedding Custom Controls

ODS Microsoft Outlook Express mailbox file

OFN Microsoft Office FileNew file

OFT Microsoft Outlook Template

OLB OLE Object Library

OLE OLE Object

OOGL object-oriented graphics library

OPO OPL output executable

P Common file extension P

Extension description

P65 PageMaker 6.5 file

PAB Microsoft Personal Address Book

PART Go! Zilla partial download file

PAS Pascal source code

PY Python source code

PYC Python bytecode file

PYW Python graphics window file

PBD PowerBuilder dynamic library as an alternative to native DLL

PBL for PowerBuilder dynamic library in PowerBuilder development environment

PBM exportable bitmap

PBR PowerBuilder Resources

PCD Kodak Photo-CD image; P-Code compiler test script, tested by Microsoft and Microsoft Visual

PCL Hewlett-Packard printer control language file (printer spare bitmap)

PCM sound file format; OKI MSM6376 synthesis chip PCM format

PDD Graphic image that can be opened with Paint Shop Pro or other image processing software

PDF Adobe Acrobat exportable document format file (displayable by web browser); Microsoft Systems Management Server package definition file; NetWare printer definition file

PFM printer font scale

PGL HP Plotter Drawing File

PGM can output grayscale image (bitmap)

PH temporary file generated by the Microsoft help file compiler

PHP / PHP3 HTML pages with PHP scripts

PHTML HTML pages containing PHP scripts; HTML interpreted by Perl

PIC PC drawing bitmap; Lotus picture; Macintosh PICT drawing

PJX / PJT Microsoft Visual FoxPro Project File

PKG Microsoft Developer Studio application extension (similar to DLL file)

PNG Portable Network Graphic Bitmap; Paint Shop Pro Browser Catalog

POT Microsoft Powerpoint module

PPA Microsoft Powerpoint Interposer

Pinnacle program files for PPF Turtle Beach

PPM Portable Pixel Map Bitmap

PPS Microsoft Powerpoint Slide Show

PPT Microsoft Powerpoint presentation

PRF Windows system files, Macromedia director settings files

PRG dBASE Clipper and FoxPro program source files; WAVmaker program

PRJ 3D Studio (DOS) project file

PRN print form (space-separated text); DataCAD Windows printer file

PRT print format file; Pro / ENGINEER component file

PSD Adobe photoshop bitmap file

PSP Paint Shop Pro image file

PST Microsoft Outlook Personal Folder File

PWZ Microsoft Powerpoint Wizard

Q Common file extensions beginning with Q

Extension description

QIC Microsoft backup file

QIF QuickTime related image (MIME); Quicken import file

QLB Quick library

QRY Microsoft Inquiry File

QTP QuickTime Priority File

QTX QuickTime related images

QW Symantec Q & A Write program file

R Common file extensions beginning with R

Extension description

RA RealAudio sound file

RAM RealAudio Metafile

RAR RAR archive (Eugene Roshall format)

RDF resource description framework file (involving XML and metadata)

REG registry file

REP Visual dBASE report file

RES Microsoft Visual C ++ resource file

RFT editable form text (part of IBM's DCA or part of the document content framework structure)

RGB / SGI Silicon Graphics RGB File

RM RealAudio Video File

RMD Microsoft RegMaid Document

RPT Microsoft Visual Basic Crystal report file

RTF Rich Text Format Document

Extensions used by RUL InstallShield

RVP Microsoft Scan Configuration File (MIME)

S Common file extensions starting with S

Extension description

S assembly source code file

SAV game save file

SBL Shockwave Flash Object File

SCC Microsoft Source Safe file

SCF Windows Explorer command file

SCP dial-up network script file

SCR Windows screen saver; fax image; script file

SCT SAS directory (DOS); Scitex CT bitmap; Microsoft FoxPro form

SCX Microsoft FoxPro Form File

SDT SmartDraw template

SDV semicolon-separated value file

SDX Standard File for SDX Compressed MIDI Sample Dump

SEP Tag Image File Format (TIFF) bitmap

SFD SoundStage sound file data

SFI Sound Stage sound file information

SFR Sonic Foundry Sample

SFX RAR self-extracting file

SGML Standard Generalized Tag Language

SHG hotspot bitmap

SHTML HTML file with server-side include (SSI)

SHW Corel Show presentation

SIG symbol file

SKA PGP key

SKL Macromedia Director Resource File

SL PACT Save Layout Extension

SO Linux shared library

SPL Shockwave Flash object; DigiTrakker sampling

SQC Structured Query Language (SQR) plain code file

SQR Structured Query Language (SQR) program file

STR screen saver file

SWA Shockwave Sound File in Macromedia Director File (MP3 File)

SWF Shockwave Flash Object

SYS system file

SYW Yamaha SY Series Wave File

T Common file extensions beginning with T

Extension description

TAZ UNIX gzip / tape archive

TGA Targa bitmap

THEME Windows Desktop Theme File

THN Graphics WorkShop for Windows sketch

TIF / TIFF Tagged Image File Format (TIFF) bitmap

TIG tiger file used by the US government to distribute maps

TLB OLE Type Library

TMP Windows temporary files

TOL Kodak Photo Enhancer

TPL CakeWalk sound template file; DataCAD template file

TRM terminal file

TRN MKS Source Integrity Engineering Usage Log File

TTF TrueType font file

TXT ASC sound data in text format

TXW Yamaha TX16W Wave File

U Common file extensions beginning with U

Extension description

UDF Windows NT / 2000 Unique Database File

ULT Ultra Tracker Music Module (MOD) file

URL Internet Shortcut File

USE MKS source integrity file

UWF Ultra racker wave file

V Common file extensions beginning with V

Extension description

VBP Microsoft Visual Basic project file

VBS Microsoft Visual Basic scripting language

VBW Microsoft Visual Basic workspace file

VBX Microsoft Visual Basic user-defined control

VCT / VCX Microsoft FoxPro Class Library

VDA Targa bitmap

VIR Norton Anti-Virus or other antivirus products are used to identify files infected by a virus

VIV VivoActive Player streaming video files

VSD Visio drawing file (flow chart or diagram)

VSL Download List File (GetRight)

VSS Visio template file

VST Targa bitmap

VSW Visio Workspace File

VXD Microsoft Windows Virtual Device Driver

VBP Microsoft Visual Basic project file

VBW Microsoft Visual Basic workspace file

VBX Microsoft Visual Basic user-defined control

VDA Targa bitmap

VIR Norton Anti-Virus or other antivirus products are used to identify files infected by a virus

VQF Yamaha Sound-VQ file (standard may appear)

VSD Visio drawing file (flow chart or diagram)

VSL Download List File (GetRight)

VSS Visio template file

VST Targa bitmap

VSW Visio Workspace File

VXD Microsoft Windows Virtual Device Driver

W Common file extensions beginning with W

Extension description

W3L W3Launch file

WAB M icrosoft Outlook file

WAD Large files of DOOM games containing videos, player levels and other information

WAV Windows Waveform

WBK Microsoft Word backup file

WCM WordPerfect Macro

WDB Microsoft Works Database

WFM Visual dBASE Windows Form

WFN symbols used in CorelDRAW

WIL WinImage file

WIZ Microsoft Word Wizard

WLL Microsoft Word interposer

WMF Windows Metafile

WOW Grave Composer music module (MOD) file

WP WordPerfect document

WPD WordPerfect document or presentation

WPF Word Processing Document

WPG WordPerfect graphics

WPS Microsoft Works Document

WPT WordPerfect template

WR1 Writer Document

WRK Cakewalk Music Sound Project File

WRL virtual reality model

WRZ VRML file object

X Common file extension X

Extension description

X AVS image format

XAR CorelXARA Painting

XBM MIME "xbitmap" image

XI Scream Tracker Device Sample File

XLA Microsoft Excel interposer

XLB Microsoft Excel toolbar

XLC Microsoft Excel charts

XLD Microsoft Excel dialog

XLK Microsoft Excel backup

XLL Microsoft Excel interposer file

XLM Microsoft Excel Macro

XLS Microsoft Excel worksheet

XLT Microsoft Excel template

XLV Microsoft Excel VBA module

XLW Microsoft Excel Workbook / Workspace

XNK Microsoft Exchange Shortcut File

XPM X bitmap format

XWD X Windows Dump Format

XWF Yamaha XG Works file (MIDI sequence)

X16 macro media expansion (program expansion), 16-bit

X32 macro media expansion (program expansion), 32-bit

Y Common file extensions start with Y

Extension description

YAL Arts & Letters Clip Art Gallery

Z Common file extensions starting with Z

Extension description

Z UNIX gzip file

ZAP Windows Software Installation Configuration File

ZIP Zip file