Article · Wikipedia archive · Last revised Jun 10, 2026

List of filename extensions (A–E)

This alphabetical list of filename extensions contains extensions of notable file formats used by multiple notable applications or services.

Last revised
Jun 10, 2026
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This alphabetical list of filename extensions contains extensions of notable file formats used by multiple notable applications or services.

A

Ext. Description Used by
A Archive file ar (Unix)
AA Advanced Audio file YouTube Music
AAC Advanced Audio Coding file iOS, Nintendo DSi, Nintendo 3DS, YouTube Music
ACCDB1 Microsoft Access Database Microsoft Access Database (Open XML)
ACCFT2 Microsoft Access Data Type Template Microsoft Access
ACO Adobe color palette format (.aco)3 Adobe Photoshop4
ADT Abrechnungsdatentransfer, an xDT application Healthcare providers in Germany
ADX Document Archetype Designer
ADZ Amiga Disk Zipped (See Amiga Disk File) GZip
AGDA Agda (programming language) source file Agda typechecker/compiler
AGR ArcView ASCII grid
AHK AutoHotkey script file AutoHotkey
AI5 Adobe Illustrator Artwork Adobe Illustrator
AIFF6 Audio Interchange File Format professional audio processing applications and on Macintosh7
AIFC6 Compressed Audio Interchange File Format
AIO APL programming language file transfer format file
AMF89 Additive Manufacturing File Format Computer Aided Design Software
AMG System image file ACTOR
AML10 AutomationML AutomationML Group
AMLX10 Compressed and packed AutomationML file AutomationML Group
AMPL AMPL source code file AMPL
AMR Adaptive Multi-Rate audio
AMV Actions Media Video
ANI11 Animation cursors for Win Win95 - WinNT
ANN Annotations of old Windows Help file Windows 3.0 - XP
APE Monkey's Audio (Lossless) audio media players
APK Android application package Android
APK Alpine Linux Package Alpine Linux and derivatives
ARC12 ARC (file format)
ART13 Gerber format Cadence Allegro, EAGLE
ARW Sony Alpha RAW image format Sony
ASAX14 ASP.NET global application file
ASCX14 ASP.NET User Control
ASF15 Advanced Streaming Format (Compressed Windows audio/video) Microsoft Corporation
ASHX14 ASP.NET handler file
ASM Assembler language source TASM, MASM, NASM, FASM
ASPX Active server page extended file Microsoft Corporation
ASX16 Advanced Stream Redirector file, redirects to an ASF file (see ASF) Microsoft Corporation
ATG17 Coco/R LL(1) formal grammar Coco/R
AT318 Atrac 3 Sound/music file All Sony devices and programs with the Atrac 3+ specification
AU audio file19
AVI2021 Audio Video Interleave Video for Windows
AVIF AV1 Image File Format
AWK AWK script/program awk, GNU Awk, mawk, nawk, MKS AWK, Awka (compiler)
AX DirectShow Filter Microsoft Corporation (Video Players)
AXF22 lightweight geodatabase ESRI ArcPad

B

Ext. Description Used by
B BASIC language source BASIC
B bc arbitrary precision calculator language file Unix bc tool
B64 base64 binary-to-text encoding23
BAK backup various
BANK24 FMOD asset file FMOD
BAR Broker Archive. Compressed file containing number of other files for deployment.25 IBM App Connect
BAS BASIC language source QuickBASIC - GW-BASIC - FreeBASIC - others
BAT Batch file MS-DOS, RT-11, DOS-based command processors
BDF Glyph Bitmap Distribution Format, a format used to store bitmap fonts. Adobe
BDT Behandlungsdatentransfer, an xDT application Healthcare providers in Germany
BEAM Executable bytecode file in fat binary format BEAM (Erlang virtual machine)26
BIB Bibliography database BibTex
BIN binary file Every OS
BLEND Blender project file Blender
BM3 UIQ3 Phone backup
BMP27 OS/2 or Win graphics format (BitMap Picture) QPeg - CorelDraw - PC Paintbrush - many
BPS WPS backup file28 Microsoft Word, Microsoft Works
BR7 Bryce 7 project file Bryce 7
BSK Bryce 7 sky presets file Bryce 7
BSON JSON-like binary serialization29 MongoDB
BSP Binary space partitioning tree file Quake-based game engines
BYU 3D geometry format30 CAD systems
BZ231 Archive bzip2

C

Ext. Description Used by
C-- C-- language source Sphinx C--
C C language source

Note that on case-sensitive platforms like Unix and with the gcc compiler the uppercase .C extension indicates a C++ source file.32

Watcom C/C++, Borland C/C++, gcc and other C compilers
C Unix file archive COMPACT
C++ C++ language source
CPP C++ language source
C32 COMBOOT Executable (32-bit) SYSLINUX
CAB33 Cabinet archive Windows 95 and later, many file archivers
CBL34 COBOL language source
CBT COMBOOT Executable (incompatible with DOS COM files) SYSLINUX
CC C++ language source
CD ASP.NET class diagram file14
CDF35 Common Data Format
CDF36 Computable Document Format Mathematica
CDP37 Trainz Railroad Simulator Content Dispatcher Pack Trainz Railroad Simulator
CDR38 Vector graphics format (drawinF CorelDraw
CDXML MIME type: chemical/x-cdxmlXML version of the ChemDraw Exchange format, CDX.39
CER40 Security certificate Microsoft Windows
CGM4142 Computer Graphics Metafile vector graphics A&L - HG - many
CHM43 Compiled Help File Microsoft Windows, Help Explorer Viewer
CHO44 ChordPro lead sheet (lyrics and chords) ChordPro and similar tools
CIA Decrypted Nintendo 3DS ROM cartridge Nintendo 3DS
CIF4546 Crystallographic Information File RasMol, Jmol
CLASS47 Java class file Java
CLS ooRexx class file ooRexx
CMD Command Prompt batch file Microsoft Windows NT based operating systems
CMD48 executable programs CP/M-86 operating system
CML Chemical Markup Language, for interchange of chemical information.49
CMOD50 Celestia Model Celestia
CN151 CNR IDL MITRE
CNOFF 3D object file format with normals (.noff, .cnoff)52 NOFF is an acronym derived from Object File Format. Occasionally called CNOFF if color information is present.53
COB54 COBOL language source GnuCOBOL
COE55 Coefficient file Xilinx ISE
COFF 3D object file format (.off, .coff)56 OFF is an acronym for Object File Format. Used for storing and exchanging 3D models. Occasionally called COFF if color information is present.57
COL DIMACS graph data format.58
COM DOS program DOS-
COMPILE14 ASP.NET precompiled stub file
CONFIG Configuration file
CPC59 Compressed image Cartesian Perceptual Compression
CPIO cpio archive file cpio
CPL60 Control panel file Windows 3.x
CPY54 COBOL source copybook file
CR261 Raw image format Canon digital cameras
CR362 Raw image format Canon R series cameras
CRAI63 CRAM index
CRAFT Holds Spacecraft Assembly information Kerbal Space Program
CRT40 Security certificate Microsoft Windows
CS64 C# language source
CSPROJ6566 C# project file Microsoft Visual Studio
CSS67 Cascading style sheet
CSO68 Compiled Shader Object, extension of compiled HLSL High-Level Shading Language
CSV69 Comma Separated Values text file format (ASCII)
CUB Used by electronic structure programs to store orbital or density values on a three-dimensional grid.70
CUBE same as .cub
CUR Non-animated cursor (extended from ICO) Windows
CXX C++ language source

D

Ext. Description Used by
D D Programming Language source file DMD
D Directory containing configuration files (informal standard) Unix
DAA Direct Access Archive
DAE COLLADA file
DAF Data file Digital Anchor
DPFHTML Extended from HTML DarkPurpleOF's Website Extension
DPFSTICKERS JSON Sticker Pack File DarkPurpleOF's Website Importable
DART Dart source file Dart
DAT AMPL data file AMPL
DAT LDraw (Sub)Part File, 3D Model LDraw
DAT Data RSNetWorx Project
DAT Data file in special format or ASCII
DAT Database file Clarion (programming language)
DAT Norton Utilities disc image data. It saves Boot sector, part of FAT and root directory in image.DAT on same drive. Norton Utilities
DAT Optical disc image (can be ISO9660, but not restricted to) cdrdao, burnatonce
DAT Video CD MPEG stream
DAT Windows registry hive (REG.DAT Windows 3.11; USER.DAT and SYSTEM.DAT Windows 95, 98, and ME; NTUSER.DAT Windows NT/2000/XP/7) Microsoft Windows
DATS Dynamic source ATS
DB Database file DB Browser for SQLite
DBA DarkBasic source code
DBC Database Connection configuration file AbInitio
DBF Native format of the dBASE database management application.71
DBG Debugger script DOS debug - Watcom debugger
DBG Symbolic debugging information Microsoft C/C++
DEB deb software package Debian Linux and derivatives
DEM digital elevation model (DEM) including GTOPO30 and USGSDEM. GTOPO30 is a distribution format for a global digital elevation model (DEM) with 30-arc-second grid spacing.72 USGSDEM is the standard format for the distribution of terrain elevation data for the United States.73
DGN CAD Drawing Bentley Systems, MicroStation and Intergraph's Interactive Graphics Design System (IGDS) CAD programs
DICOM Digital Imaging and Communications in Medicine (DICOM) bitmap DICOM Software (XnView)
DIF Data Interchange Format Visicalc
DIF Output from [diff] command - script for Patch command
DIRED Directory listing (ls format) Dired
DIVX DivX media format
DLL Dynamic-link library is a shared library. Microsoft Windows or OS/2 operating system.
DMG Apple Disk Image macOS (Disk Utility)
DMP memory dump file (e.g. screen or memory)
DN Dimension model format Adobe Dimension74
DNG75 Digital Negative, a-publicly available archival format for the raw files generated by digital cameras At least 30 camera models from at least 10 manufacturers, and at least 200 software products
DO Redo recipes; usually written in sh, but may be written in a different language with a shebang. Redo76
DOC777879 A Document, or an ASCII text file with text formatting codes in with the text; used by many word processors Microsoft Word and others
DOCM Microsoft Word Macro-Enabled Document Microsoft Word
DOCX80 Microsoft Word Document Microsoft Word
DOT80 Microsoft Word document template Microsoft Word
DOTX80 Office Open XML Text document template Microsoft Word
DPX8182 Digital Picture Exchange
DRC Dirac format video
DSC83 Celestia Deep Space Catalog file Celestia
DTA Stata database transport format.84 Stata
DTD85 Document Type Definition
DVC86 Data version control yaml pointer into blob storage
DWF Autodesk Design Web Format Design Review
DWG87 Drawing AutoCAD, IntelliCAD, PowerCAD, Drafix, DraftSight etc.
DX same as JDX and JCM.
DXF88 Drawing Interchange File Format vector graphics AutoCAD, IntelliCAD, PowerCAD, etc.

E

Ext. Description Used by
E E language source code E
E## EnCase Evidence File chunk EnCase Forensic Analysis Suite entity
E00 ArcInfo interchange file GIS software
E2D 2-dimensional vector graphics file Editor included in JFire
e57 A file format developed by ASTM International for storing point clouds and images Most software that enables viewing and/or editing of 3D point clouds
EBD versions of DOS system files (AUTOEXEC.BAT, COMMAND.COM, CONFIG.SYS, WINBOOT.SYS, etc.) for an emergency boot disk Windows 98, ME
EC Source code eC
ECC Error-checking file dvdisaster
EDE Ensoniq EPS disk image AWAVE
EDF European data format Medical timeseries storage files
EFI Extensible Firmware Interface
EIS EIS Spectrum Analyser Project EIS Spectrum Analyser Archived 2010-03-29 at the Wayback Machine
EL Emacs Lisp source code file Emacs
ELC Byte-compiled Emacs Lisp code Emacs
ELF Executable and Linkable File

EurekaLog File (contains details of an exception)

Unix

EurekaLog (https://www.eurekalog.com/)

EMAIL Outlook Express Email Message Windows Live Mail, Outlook Express, Microsoft Notepad
EMAKER E language source code (maker) E
EMF Microsoft Enhanced Metafile
EML Email conforming to RFC 5322;89 Stationery Template Email clients;Outlook Express
EMZ Microsoft Enhanced Metafile compressed with ZIP Microsoft Office suite
EOT Embedded OpenType
EP GUI wireframe/prototype project Prikhi Pencil, Evolus Pencil
EPA Award BIOS splash screen Award BIOS, XnView
EPS Encapsulated PostScript CorelDraw - PhotoStyler - PMView - Adobe Illustrator - Ventua Publisher
EPUB Electronic Publication (e-Reader format) Okular (Linux) - Apple Books - Sony Reader - Adobe Digital Editions - Calibre (LMW)
EU4 Europa Universalis 4 save game file Europa Universalis 4
ERL Erlang source code file
ES6 ECMAScript 6 file
ESCPCB Data file of "esCAD pcb", PCB Pattern Layout Design Software esCAD pcb provided by Electro-System
ESCSCH Data file of "esCAD sch", Drawing Schematics Diagram Software esCAD sch provided by Electro-System
ESD Windows Imaging Format ImageX, DISM, 7-Zip, wimlib
ESF Electronic Theater Controls, Inc. theatrical lighting show control file ETC Eos platform software and consoles
ETL event trace log file Microsoft9091
EVT Windows Event log file Microsoft Windows NT 4.0 - XP; Microsoft Event Viewer
EVTX Windows Event log file XML structured Microsoft Windows Vista, 7, 8; Microsoft Event Viewer
EX Elixir source code file Elixir programming language running on BEAM (Erlang virtual machine)92
EXE Directly executable program DOS, OpenVMS, Microsoft Windows, Symbian or OS/2
EXP Drawing File format Drawing Express
EXP Melco Embroidery Format Embroidermodder
EXR OpenEXR raster image format (.exr).56 Used in digital image manipulation for theatrical film production. EXR is an acronym for Extended Dynamic Range. Stores 16 bit per pixel IEEE HALF-precision floating-point color channels. Can optionally store 32-bit IEEE floating-point "Z" channel depth-buffer components, surface normal directions, or motion vectors.93
EXS Elixir script file Interactive Elixir (IEx) shell94
See also

See also

References

References

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External links