List of File Types

This list of file types sets out to answer the common question "What is a file of type .x?" or "What is that file extension for?"

A file type is denoted by those letters that follow the last dot in a file name. These letters denote the type of file, and are also commonly known as a file extension. On Windows PCs the file extension may be hidden by Windows, but is still part of the file name.

This list of file types contains a list of file extensions together with a brief description of the type of file that the extension is associated with.

* .a - UNIX static library file / ADA source code file.
* .ac - ACwin project file / GNU Autoconf configuration script / AC3D geometry file / Acceleration record file.
* .acc - GEM desk accessories file.
* .accdb - Microsoft Access 2007 database file.
* .ace - ACE Archiver compression file.
* .act - Action diagram (FoxPro) / Action File (Animation Master).
* .acv - Adobe Photoshop compensation curve file.
* .ade - Microsoft Access project extension.
* .adp - Microsoft Access project file / Dynamic web page.
* .adm - Addict Dictionary file / Group Policy Administrative Template file.
* .afw - Bullion firmware file.
* .agd - Agile Advantage file / AgileGraph data file.
* .ai - PostScript viewer / Acrobat Illustrator vector graphics file / AIwin project file.
* .aid - MapXtreme generated file.
* .aif - Audio Interchange File.
* .aifc - Compressed audio file.
* .aiff - Audio Interchange File.
* .ald - Axapta Label Data file.
* .alg - ESRI Mapper File / HDLmaker file.
* .als - Part of the Delphi help file system.
* .amm - Adaptive Message Macro file.
* .amp - Arbitrary Map file.
* .amv - Audio-Video media file.
* .ani - Animated cursor file.
* .aod - Microsoft Dynamics AX Application Object Data file.
* .apn - ApneaGraph data file / Wallpaper graphics file / REC Navigation application.
* .app - VoxPro file / GEM file.
* .application - ClickOnce application manifest file.
* .aps - Binary file.
* .arc - Compressed file.
* .arj - Compressed file.
* .as - Flash ActionScript file.
* .asc - ASCII text file.
* .ascx - Visual Studio custom user control source file.
* .asf - Media player audio-visual file.
* .asm - Assembler file / Solid Edge assembly file / Pro ENGINEER assembly file.
* .asp - Active Server page.
* .aspx - ASP.NET file.
* .aspx.cs - Visual C# source file.
* .aspx.resx .Net resource file.
* .aspx.vb - VB.Net source file.
* .atf - Adobe Transfer Functions file / Axon Text File.
* .att - Email attachment.
* .atx - Texture plug-in (Animation Master)
* .aty - 3D Topicscape association type file.
* .au - µ-law sound file.
* .aux - Auxiliary target file / Erdas Hierarchical File / LaTeX auxiliary reference file / ChiWriter auxiliary dictionary.
* .av2 - Avatar2 model file (Animation Master)
* .ava - Avatar model file (Animation Master)
* .avi - Audio video file.
* .awk - AWK script file.
* .axe - AutoRoute map export file.
* .axr - ARCHPR project status file.
* .bad - Generic bad (corrupt) file / Non-delivered email.
* .bak - Generic backup file.
* .bas - BASIC source code file.
* .bat - MS-DOS batch file.
* .bbc - BBC BASIC for Windows program or data file.
* .bbt - BTwin database file / bbTracker GPS track file / Basket Ball Team file.
* .bc - BCwin project file / BitComet intermediary download file / Big Crunch compressed archive / Byte Code (LLVM) file.
* .bcd - Board/Chip description file.
* .bck - VMS backup file.
* .bdb - Back of Works database file.
* .bdp - Bad mail pointer file / Combat Flight Simulator 3 file.
* .bdr - Bad mail report file / Microsoft Publisher Border file.
* .bfc - Windows Briefcase file.
* .bil - Spot raster image file.
* .bin - Generic binary / MacBinary encoded file / CD image.
* .bk - Adobe FrameMaker book file.
* .bkf - Windows backup file.
* .bkp - backup file
* .bks - Backup selection file.
* .blk - Descent Mission Builder block file.
* .bmc - Bitmap Cache file / Embroidery image file.
* .bmp - Bit-map image file.
* .bnk - Decent 2 FM sound instrument definition file.
* .bpg - Borland Delphi project group file.
* .bpl - Borland package library.
* .brd - Layout file for EAGLE EDA system / BizInt Smart Charts file.
* .brn - BrainStorm model file.
* .brw - ProMash session file.
* .bsc - Browse information file.
* .bt - BTwin project file / EVwin project file / ILwin project file.
* .btk - TeKton database file.
* .btm - Batch to memory file.
* .bu - Pegasus mail temporary file.
* .bud - Backup disk for Quicken.
* .bup - Backup of a .ifo file.
* .bva - Biovision action file.
* .bvh - Biovision hierarchical motion file.
* .bvp - BlueVoda Publication file.
* .bz2 - Bzip2 compressed file.
* .c - 'C' programming language source code.
* .c4d - Clonk object definition file.
* .c4f - Clonk scenario folder file.
* .c4p - Clonk player file.
* .c4m - Clonk material file.
* .c4i - Clonk object info file.
* .c4s - Clonk scenario file.
* .c4q - Clonk queue file.
* .c4v - Clonk video file.
* .cab - Cabinet compressed file.
* .cam - Camera file (Animation Master).
* .cat - Security catalogue file.
* .cbl - Cobol source file.
* .cc - C++ source file.
* .ccd - CloneCD control file.
* .cct - Adobe Director protected cast resource file.
* .cd - Class diagram file / CD-i OptiImage CD image file / cdTree CD catalogue file.
* .cd4 - Dymo DiscPainter file.
* .cda - Compact disk audio track.
* .cdd - Claris Draw graphics file / CVI symbol table / CADEX drawing / ConceptDraw document / UML file.
* .cdl - SignLab vector graphics file / Common Data Language file / CAD Advanced Design Language file.
* .cdr - CorelDRAW drawing / Raw Audio-CD.
* .cdt - Corel Draw template file.
* .cdx - Visual FoxPro compound index.
* .cer - Certificate file.
* .cf - CFwin project file / Sendmail configuration file / Piranha configuration file / Zimbra configuration file.
* .cfm - Cold Fusion mark-up file
* .cfml - Cold Fusion mark-up language file.
* .cfg - Delphi configuration file / Outlook configuration file / Netgear router configuration backup file.
* .cgf - CargoMap file.
* .cgi - CGI web based program or script.
* .che - CHwinEHE project file / Chemical model file.
* .chi - Help file index / ChiWriter document.
* .chm - Compiled HTML help file.
* .chml - Chameleon encrypted file.
* .cho - Choreography file (Animation Master)
* .chr - Charset file / Constraint Handling Rules file.
* .chunk001 - First part of a File Splitter split file.
* .chunk002 - Second part of a File Splitter split file.
* .chunk003 - Third part of a File Splitter split file.
* .cif - Easy CD Creator CD image file.
* .cl - Common LISP source file / CLwin project file / Control Language file.
* .class - Compiled Java class file.
* .clp - Windows clipboard file.
* .cls - Latex class file / VB6 class file / GSEA Phenotype data format file.
* .clw - Class Wizard file / Clarion module file.
* .cmd - Windows-DOS command script file.
* .cmf - Corel Metafile.
* .cml - PADGen company information file / Chemical Markup Language file.
* .cn - CNwin account file / MIwin account file / ICM distance restraints file.
* .cnt - Contents file for a windows help file.
* .cnx - Pegasus mail temporary file.
* .com - Executable command file.
* .conf - Configuration file.
* .config - NUnit Configuration file.
* .coo - Coordinates file.
* .cos2 - Pinnacle Studio file.
* .cpl - Control panel item file.
* .cpp - C++ language source file.
* .cpt - Compact Pro file.
* .cr5 - Survey Pro coordinates file.
* .crt - Security Certificate file.
* .cs - Visual C# source file.
* .csp -Crystal Server Page / Caché Server Page.
* .csproj - C# project file.
* .css - Cascading style sheet file.
* .cst - Adobe Director protected cast resource file / DesignWorks schema file / LogicWorks schema file.
* .csv - Comma separated value file.
* .ct - CTwin project file / Nucleic acid sequence and base pairing information file / Cheat table file.
* .ctl - Visual Basic Control source code file.
* .ctt - Messenger contacts file.
* .ctx - Visual Basic Control file / Ciphertext (encrypted text) file / Creativyst Table Exchange Format file / CyberTracker eXport file / Text file / Terminal Server .ini file backup.
* .cue - Cue sheet file.
* .cur - Microsoft Windows cursor file.
* .cvs - CANVAS file.
* .cvx - CANVAS file.
* .cwf - ClarisWorks file / COM-Watch File.
* .cxt - Macromedia Director protected cast resource file.
* .cxx - C++ language source file.
* .da - DAwin project file.
* .daa - Direct-Access-Archive CD/DVD image file
* .dat - Generic data file / Mapinfo data file / c-tree plus database.
* .db - Generic database file / Borland Paradox database file / Thumbnail cache.
* .dbc - Visual FoxPro database file.
* .dbf - dBASE III database file / dBASE IV database file / dBASE 5 database file / FoxPro database file / ArcView dBASE file.
* .dbg - MS-Dev debug file.
* .dbi - Delphi Database Explorer file.
* .dbx - FoxPro table file / Outlook Express file.
* .dcf - Copy protected media file container.
* .dci - Delphi code template file.
* .dcp - Delphi component package.
* .dcr - Delphi component resource file / Shockwave file
* .dct - Delphi file / FoxPro file / Aurora dictionary.
* .dcu - Delphi compiled unit.
* .dcx - FoxPro database index.
* .dd - DDwin project file / Mac Disk Doubler compressed archive file.
* .ddf - Diamond Directive File.
* .ddi - DiskDupe image file.
* .ddp - Delphi diagram portfolio file.
* .deb - Package file.
* .debuglog - MyDefrag log file.
* .def - Windows library definition file.
* .dem - Delphi file / Descent 1/2 demo file.
* .dep - Dependency file.
* .deploy - Deployable .NET file / DeployMaster file.
* .der - Security Certificate file
* .det - Descent Manager file.
* .dfm - Delphi form file.
* .dfn - Delphi support file for integrated translation environment.
* .dft - Solid Edge drafting file.
* .dir - Shockwave file.
* .dg - Auto-trol vector graphics drawing file.
* .dgn - MicroStation binary design file.
* .dlg - Windows dialog resource file.
* .dll - Dynamic Linked Library.
* .dlm - (Microsoft) DownLoad Manager file / Akamai Download Manager file / 3ds Max file.
* .dmg - Macintosh Disk Image.
* .dmp - (Windows) Dump file.
* .dmt - Delphi menu template file.
* .do - ModelSim file / Stata command file.
* .doc - Word document / Word Perfect document.
* .docx - Microsoft Word (XML) document.
* .dof - Delphi options file.
* .dot - Microsoft Word template.
* .dotm - Microsoft Word 2007 template supporting macros.
* .dotx - Microsoft Word 2007 template.
* .dpk - Delphi package.
* .dpl - Delphi 3 package library.
* .dps - DataPower script file.
* .dr - DRwin project file / Digital Rights file / Disaster Recovery file.
* .dro - Delphi object repository file.
* .dpr - Delphi project file.
* .drv - Driver file.
* .drw - Brother word-processor file / Freelance file / Micrografx file / Autocad drawing / LinkWinds drawing.
* .DS_Store - Mac OS X file describing the appearance of a folder.
* .dsk - Delphi desktop file.
* .dsm - Delphi symbol module / Visual Studio macro file.
* .dsn - Tiny CAD file / ODBC File DSN.
* .dst - Delphi desktop settings file.
* .dti - Delphi 5 diagram portfolio file.
* .dtp - Timeworks publisher text file.
* .dun - Dial-up networking configuration file.
* .dvf - Digital Voice File / Digital View Cam file.
* .dvr-ms - Digital Video Recorder file.
* .dwf - AutoCAD drawing.
* .dwfx - AutoCAD drawing file.
* .dwg - AutoCAD binary drawing.
* .dwt - AutoCAD binary drawing template / Dreamweaver page template file / Expression Web Dynamic Web Template file.
* .dxb - AutoCAD binary drawing exchange format.
* .dxf - AutoCAD drawing exchange format file.
* .dxr - Macromedia Director Protected movie file.
* .e00 - ArcInfo export file.
* .eb - EBwin project file.
* .ecf - Extension Configuration file / Sage CRM component file.
* .ect - Exception Console Template file.
* .ecw - Enhanced Compressed Wavelet.
* .edb - Extensible Storage Engine database page file / Exchange database file / Windows update data store file / XEphem database file / Windows Search index database file.
* .elx - Elixir Form Design Suite file.
* .emf - Enhanced Windows Metafile.
* .eml - Microsoft Outlook e-mail file.
* .end - CorelDraw arrow-head definition.
* .epf - EAGLE Preferences file / Encapsulated PostScript file / Entrust profile file.
* .eps - Encapsulated postscript file.
* .eps2 - Adobe PostScript Level II.
* .err - FoxPro compilation error file.
* .es - Sage CRM component script file.
* .esl - FoxPro support library file.
* .evt - Event log file.
* .exe - Executable file / Self extracting archive.
* .exp - LIB export file / SonicWall exported configuration file.
* .ezs - EZ-R Stats batch script file.

* .fas - Fast load lisp file.
* .fcc - FreeProxy cache control file.
* .fcd - Virtual CD-ROM file / FreeProxy cache data file / Flowcode file.
* .fcg - FastCGI script.
* .fd - MO5 disk image file.
* .fdp - FlashDevelop project file / MapSonic memory card format map file / FileDisk Protector file.
* .fes - 3D Topicscape fileless occurrence file.
* .ffa - Fast Find file.
* .ffl - Fast Find file.
* .ffo - Fast find file.
* .ffx - Fast find file.
* .fh - Simplex database form file.
* .fky - FoxPro macro file.
* .fla - Flash movie file.
* .flk - Flock plugin (Animation Master)
* .fll - FoxPro dynamic link library.
* .flv - Flash Video File.
* .fm - Adobe FrameMaker document file.
* .fmt - FoxPro format file / Tharo Systems label file.
* .fnt - Font file / Descent font file.
* .fol - First Choice Database file.
* .fon - System font file.
* .for - Fortran source code file.
* .force - Microsoft Visual Studio file.
* .fp - FinePrint AutoSave file / FoxPro configuration file / CRiSP Fishery Policy file.
* .fp5 - Filemaker Pro database file.
* .fp7 - FileMaker Pro database file.
* .fpt - Foxpro table memo.
* .fpx - FlashPix image file.
* .frm - Visual Basic source code / MySql table definition file.
* .frt - FoxPro report.
* .frx - FoxPro report / Visual Basic form binary file.
* .fts - Help index file.
* .ftw - Family Tree Maker export file
* .fxp - FoxPro compiled program.
* .gbi - Delphi database explorer file / gBurner Image file.
* .gbm - MapServer bitmap store file.
* .gdb - MapServer database file / Interbase file.
* .gds - MapServer dataset file.
* .ged - GEDCOM file.
* .gem - GEM metafile.
* .gen - ARC Digitized graphics file / Compressed Digitized Graphics file
* .gid - Windows (help) global index.
* .gi - Global Image file.
* .gif - GIF image file.
* .gix - MapServer sheet index file.
* .gjm - Compressed audio file (mono).
* .gjs - Compressed audio file (stereo).
* .gmt - Zmodeler2 filter file.
* .gpd - Generic Printer Driver file / CRISP output file / Gameplay data file / Grid Parameter Definition file / Visual Epr input file.
* .gra - Gradient plugin (Animation Master).
* .grc - Vertical Mapper Classified Grid file.
* .grd - Vertical Mapper Continuous grid file / RockWorks XYG data file.
* .grp - Program Manager Group file.
* .gsf - MapServer sheet file.
* .gvp - Google Video Player File.
* .gz - Unix compressed file.
* .gzip - Compressed file.

* .h - Header file.
* .hal - HAL code source file.
* .ham - Descent 2 game data attribute file.
* .hcsp - HTML page generated from Stellent CMS.
* .hdb - Hansa DataBase file.
* .hdmp - Windows Heap Dump File.
* .hex - Macintosh binary file.
* .hhc - HTML Help Workshop Contents file.
* .hhf - Hand Held Format file / HLA Header file.
* .hhk - HTML Help Workshop Index file.
* .hhp - HTML Help Workshop Project file.
* .hi - Descent 2 high score file.
* .hlp - Windows standard help file.
* .hmp - Music file.
* .hog - Descent 1/2 archive file.
* .hol - Microsoft Outlook Holiday file.
* .hpp - C++ header file.
* .hqx - Macintosh binary file.
* .ht - HyperTerminal file.
* .hta - Hypertext Application.
* .htm - HTML file.
* .html - HTML file.
* .htt - Folder settings file.
* .hxm - Descent 2 game data attribute file.
* .hxt - Hash extension plugin (Animation Master).
* .hxx - C++ header file.
* .i00 - WinPhone phonebook / DVD Shrink.
* .i - Borland C++ intermediary file.
* .ic - ASwin project file.
* .icf - Information (Model) Configuration file / ICOM (CS-R20) communications file.
* .icl - Icon Library File.
* .icm - Image Color Matching profile.
* .ico - Windows icon file.
* .ics - Calendar data exchange file / SwiftView command file / IronCAD Scene file / Isochrone save file.
* .id - MapInfo index file.
* .idb - MS-Dev intermediate file.
* .idx - FoxPro index file / C-tree plus index file.
* .if - CRwin project file.
* .ifo - CD/DVD Information file.
* .iif - QuickBooks import file.
* .img - GEM image file / CloneCD image file / CD image file / Erdas Hierarchical Image file / LinkSys firmware image file.
* .imh - Incredimail email index file.
* .imm - iMindMap mind-map file / IncrediMail e-mail file.
* .imp - eBook import file / Simply Accounting file / Compressed archive / FileMaker Pro data filter / Desktop Dispatcher import file / WINGS GIS export file.
* .in - GNU Autoconf configuration script.
* .ind - MapInfo index file.
* .inf - Information file.
* .ini - Initialisation file.
* .ink - Mimio presentation / Pantone reference fills file.
* .inl - Inline file.
* .ins - Internet Naming Service file / InstallShield script.
* .isd - MySql data file.
* .ism - MySql index file.
* .iso - CD image file.
* .iss - Inno Setup Script / InstallShield Silent response file.
* .iwp - Interactive web physics file / Wang WP file / Generated web page.
* .jad - Java Application Descriptor.
* .jar - Java Archive.
* .java - Java source file.
* .jfif - JPEG graphics file.
* .jgw - JPEG world file
* .jhtm - Java Server page
* .jhtml - Java Server page.
* .jnl - CVS journal file.
* .job - Windows Task Scheduler Job / Tripod Data Systems job file / MetaCAM Nest job file.
* .jpg - JPEG graphics file.
* .jpeg - JPEG graphics file.
* .jpe - JPEG graphics file.
* .jpr - JBuilder project file.
* .jpx - JBuilder project file.
* .jrs - Reserve transaction log file.
* .js - JavaScript file.
* .jsf - JourneyMan Session File / JavaServer Faces file.
* .json - JSON data interchange file.
* .jsp - Java Server page.

* .k7 - MO5 tape image file.
* .klb - F-Secure anti-virus signature update file.
* .kfm - Keyframe Motion file (Animation Master).
* .kml - Keyhole Markup Language file (Google Earth)
* .kmz - Compressed keyhole markup language file.
* .l - LEX source file
* .lab - Excel mailing labels file / Codesoft Systems label software template file.
* .lbl - Tharo Systems output label file.
* .lbr - Library file (Animation Master).
* .lbt - FoxPro label memo.
* .lbx - FoxPro label.
* .ldf - SQL Server database log file.
* .ldif - LDAP Data Interchange file / Netscape address book export.
* .ldr - LDraw drawing file
* .lgo - Windows start-up logo file.
* .lha - Compressed file.
* .lib - Library file.
* .lic - Component license file / Generic license file.
* .lit - eBook / Light file.
* .lnk - Windows shortcut.
* .log - Generic log file.
* .log1 - Generic log file / Windows Registry hive log file.
* .log2 - Generic log file / Windows registry hive log file.
* .lsp - AutoCAD lisp program.
* .lst - Listing file / FoxPro file / Playlist file / Kaspersky black-list file / PowerPoint play list file / SAS output listing file.
* .lyt - MetaCAM layout file.
* .lzh - Compressed file.
* .m1v - MPEG movie.
* .m2ts - Sony high definition video file.
* .m3u - MP3 play list.
* .m4a - Apple Inc MPEG 4 file.
* .m4r - iPhone ringtone file.
* .map - Linker map file / MapInfo file / Manifold project file.
* .maq - Access query.
* .mar - Access report.
* .mat - Material file.
* .max - PaperPort image file.
* .mbm - MultiBitMap file.
* .mbs - Opera mailbox / Multi bit series file / Master Bibliography style file / MR Tech Zip backup / Macrografx Picture Publisher Brush / Mailbag assistant script.
* .mcd - Motion capture plugin (Animation Master).
* .mco - MSN messenger winks file / XtraMusic file (tentative).
* .md5 - Shorten audio checksum file / MD5 checksum file.
* .mda - MicroDesign area file.
* .mdb - Access database.
* .mde - Access database (compiled).
* .mdf - SQL Server database file / CD image file.
* .mdl - Rose model file / Animation Master model file.
* .mdmp - Windows Minidump file.
* .mdp - MicroDesign page file.
* .mds - CD image file.
* .mdx - MapServer database index file / dBase index file.
* .mgl - Mascopt network graph file / plvdkey management summary file.
* .mht - Web archive file.
* .mhtml - Modular Hyper Text Mark-up Language web page / Web archive file.
* .mid - MIDI file / MapInfo interchange file.
* .mif - MapInfo interchange file.
* .mim - A MIME file.
* .mix - Power C object file / Command and Conquer file / PhotoDraw picture / Picture IT! picture / Dance eJay music mix.
* .mkv - Matroska video file.
* .mm - FreeMind mind map file / Matrix Market file.
* .mma - Musical MIDI Accompaniment song file / Master Album Maker Album.
* .mmap - MindManager mind-map file.
* .mmd - Mail Message Download file
* .mn2 - Descent 2 mission file.
* .mod - Windows kernel module.
* .modd - Picture Motion Browser data file.
* .moff - Picture Motion Browser index file.
* .mol - Molfile.
* .mot - Motion file.
* .mov - QuckTime movie.
* .movie - Silicon Graphics movie.
* .moz - Netscape cache file.
* .mp2 - MPEG 2 audio file.
* .mp3 - MPEG 3 audio file.
* .mp4 - MPEG 4 audio file.
* .mpc - Musepack (audio) file.
* .mpd - Multi Part Dat file.
* .mpe - MPEG movie.
* .mpeg - MPEG movie.
* .mpg - MPEG movie.
* .mpp - Microsoft Project file / CAD drawing file.
* .mpt - Microsoft Project template file.
* .msc - MMC snap-in file / CRiSP fish stocks file.
* .msdvd - Windows DVD Maker project file.
* .mse - MSwinEHE project file.
* .msf - Thunderbird Mail Summary file / Miranda IM skin file.
* .msg - Outlook message file / Fidonet message.
* .msi - System installer package.
* .msm - System installer merge module.
* .msn - Descent 1 mission file.
* .msp - Microsoft System Installer Patch file / Midi Studio Project file.
* .mspx - ASP.NET file.
* .mst - Microsoft System Installer Transform file
* .msv - Memory Stick Voice file / MyStars saved file.
* .mvl - Descent 2 movie archive.
* .mws - MapInfo workspace file.
* .mxml - Adobe Flex interface markup file.
* .myd - MySQL data file / MyDefrag script.
* .myi - MySQL index file.
* .nb - Nota Bene document file.
* .nba - Nero BackItUp compressed archive.
* .ncb - Visual Studio browse file.
* .ncf - Netware command file.
* .nch - Outlook express news items / Audio file / Virus.
* .ndf - Secondary SQL Server data file.
* .nds - Nintendo DS binary file.
* .ndx - dBase non-maintained index file.
* .newsrc - Newsgroup source file.
* .nk2 - Microsoft Outlook Nickname file.
* .nlm - Netware loadable module.
* .nfb - Nokia Phone (Fone) Book, backup file.
* .nls - National language code page file.
* .nn - Nero CD file list.
* .npk - MicroTik RouterOS upgrade package / n-Track Studio temporary file.
* .nrg - Nero CD image.
* .ns - NSwin project file / NetStumbler log file.
* .nsf - Lotus notes database file.
* .ntf - National Imagery Transmission format.
* .nunit - NUnit Test Project file.
* .nut - Nutricalc file.
* .nwc - NoteWorthy composer music score / NavisWorks Cache file.
* .nws - Newsgroup article file / Newsmaster II data file.
* .nzb - Newzbin file.
* .o - Object file.
* .obj - Object file (Windows)
* .oca - VB cache file.
* .ocx - ActiveX control.
* .od - Mascopt graph request file.
* .ods - OpenOffice spreadsheet / Outlook Express mailbox.
* .odt - OpenDocument Text document / Virtual Reality Explorer Kit Object file.
* .oeb - Open eBook file.
* .oft - Outlook form template file.
* .ogg - Ogg Vorbis music file.
* .old - Generic old or backup file.
* .opf - FlipBook definition file
* .opt - Visual studio workspace information file.
* .orf - Olympus Raw File / Descent 3 Outrage Room Format file / Override Rules File.
* .ost - Exchange offline storage file.
* .ovl - Driveimage setup file / Overlay file.

* .p - Progress 4GL code file / Pascal source file.
* .p12 - Personal Information Exchange file.
* .pab - Microsoft Outlook address book.
* .pak - WAD file.
* .pal - Generic colour palette files / Paint Shop Pro colour palette file / PiXCL palette file.
* .paq8o10t - PAQ compressed archive.
* .par - Windows 3.x swap file.
* .part - Partial downloaded file.
* .pas - Pascal source file.
* .pbm - Portable bitmap image file.
* .pcd - Kodak photo CD image.
* .pch - Precompiled header file.
* .pce - Eudora mail file.
* .pcl - Printer Control Language file.
* .pct - Macintosh drawing file.
* .pcx - PC Paintbrush image file.
* .pd - Paradox database file / Perl data file.
* .pdb - Program Database / Palm document.
* .pdd - Adobe PhotoDeluxe image file.
* .pde - PowerDesk encrypted file or folder / Principalm data export file / Processing development environment sketchbook file / Pathology data exchange file / Arduino script file.
* .pdf - Portable Document Format / Printer description file.
* .pdg - MetaCAM part file.
* .pf - Windows Prefetch file
* .pfx - PostEffect plug-in file (Animation Master) / Personal Information Exchange file.
* .pgt - Compiled Tags database / Sothink Glanda Widget Tools File.
* .php - PHP script file / Server side scripting file.
* .pic - Lotus graphic file / Micrografx Draw! file / Pegasus image file / SoftImage frame.
* .pict - Apple Mac internal picture format file.
* .pif - Executable / graphics file / compressed archive.
* .pig - Descent texture data.
* .pjp - JPEG graphics file.
* .pjpeg - JPEG graphics file.
* .pk7 - Signed Electronic bill.
* .pkl - Packing list file.
* .pl - Perl script.
* .plg - Visual Studio build log.
* .plist - Property list file / Preference file / Handbrake Presets file.
* .plr - Descent player file.
* .pls - Generic playlist file.
* .plt - Plot file.
* .ply - Poly model file (Animation Master).
* .pm - Perl Module / Pegasus mail file.
* .pm3 - PageMaker 3.0 document.
* .pm4 - PageMaker 4.0 document.
* .pm5 - PageMaker 5.0 document
* .pm6 - PageMaker 6.0 document
* .pm$ - Pegasus mail temporary file.
* .pml - Process Monitor log file / PADGen program information file.
* .pmd - Published map document.
* .pms - Pegasus mail signature file.
* .png - Graphics file.
* .pof - Descent 1 3D data file.
* .pog - Descent texture data.
* .pol - System policy file.
* .pot - PowerPoint design template.
* .ppd - PostScript printer description / PowerPoint slide show.
* .ppm - Portable pixelmap image.
* .ppp - Page Plus file / AIRSAR log file / Enfocus PDF Profile.
* .pps - PowerPoint slide show / Ping Plotter file.
* .ppt - PowerPoint presentation file.
* .ppz - PowerPoint animation file / Packed PowerPoint file.
* .prb - xyAlgebra probabilities file / DMSolver problem file / Silicon Explorer Probe file / Phat probabilities file.
* .pre - Render preset file (Animation Master).
* .prf - Outlook Profile file / ClarisWorks Preferences File / Macromedia Director Preferences file.
* .prg - FoxPro or dBASE source file.
* .prj - PC Guard project file / Animation Master project file.
* .prn - Print file.
* .pro - Pro/ENGINEER configuration file / Euphoria profile listing file.
* .pro2 - Euphoria time profile listing file.
* .prt - Pro ENGINEER part file.
* .ps - PostScript file.
* .psd - Native Adobe Photoshop format.
* .psp - Paint Shop Pro image.
* .pst - Personal folder file (Microsoft Outlook) / PostEffect file (Animation Master).
* .pub - Microsoft Publisher document.
* .py - Python source file.
* .pwl - Windows (9x) password file.
* .px - Paradox database index file.

* .qh - Simplex database query file.
* .qif - Quicken import file.
* .qt - QuickTime movie.
* .qxd - QuarkXPress document.
* .qxp - QuarkXPress document.
* .r - Pegasus Mail resource file
* .r00 - Part of a RAR archive
* .r01 - Part of a RAR archive.
* .r02 - Part of a RAR archive.
* .r03 - Part of a RAR archive.
* .r04 - Part of a RAR archive.
* .r05 - Part of a RAR archive.
* .ra - RealAudio file.
* .ram - RealAudio meta file.
* .rar - Compressed file.
* .raw - Raw binary image file.
* .rc - Resource file.
* .rdf - Resource Description Framework file.
* .rdi - Remote desktop connection file.
* .rdl - Descent 1 level file.
* .rdlc - Client Report Definition file.
* .rec - Rational Robot test script / ArcServe backup file / Audio-visual media file / RSA SecurID file / ProMash recipe file.
* .res - Resource file.
* .resx - .Net resource file.
* .rdo - Rawster document object.
* .reg - Windows registry file.
* .rh - Simplex database report.
* .rl2 - Descent 2 level file.
* .rm - RealAudio video file.
* .rom - MO5 cartridge image file.
* .rpm - RedHat package manager.
* .rps - Delphi translation repository file / SamStock journal file.
* .rpt - Crystal Report file.
* .rsp - Response file / ODBC driver configuration file.
* .rt - RealText file.
* .rtd - RagTime data file.
* .rtf - Rich text file.
* .rtx - Rich text file.
* .ru - Javasoft JRE lib file / Media file.
* .rw5 - TDS Raw Data file.
* .s7i - Seed7 library or include file.
* .sas - SAS program.
* .sas7bdat - SAS data set file.
* .sas7bvew - SAS data set view file.
* .sav - Generic backup file / Generic save file / Game save file / SPSS data file.
* .sbh - Rational robot header file.
* .sbl - Graphic symbol library file / Rational robot language file / Softbridge Basic language script.
* .sbn - Driver 3 game file / ArcView spatial index file.
* .sbr - Source browse file.
* .sbx - Adobe Illustrator Tsume File / ArcView spatial index file.
* .sca - Scala script file.
* .scb - Published Scala script file / Scribble document file / AI scripting file / Supercard eBook file.
* .scc - Source safe integration file.
* .scf - Windows Explorer Command file / DNA Baser file / LabView tag file.
* .sch - Scheme file (Animation Master).
* .scr - Screen saver / AutoCAD script file
* .scs - SuperTable data file.
* .scm - ICQ Sound Compressed Sound Scheme file.
* .sd7 - Seed7 source file / SAS dataset file.
* .sds - Open Office chart file / Star Office chart file / MIDI Sample dump file / Digital Space browser link / Smart Diary Suite database.
* .sea - StuffIt file.
* .sgml - Standard generalised mark-up language file.
* .sh - Shell script.
* .shd - Shader plugin (Animation Master).
* .shn - Compressed audio file.
* .shp - ArcView shapefile / AutoCAD shape definition file.
* .shs - Scrap object file.
* .shtml - HTML file supporting server side includes.
* .shx - ArcView index file / AutoCAD shape file.
* .sid - MrSID file.
* .sif - Windows unattended install answer file.
* .sis - Symbian/EPOC OS installation file.
* .sit - Macintosh StuffIt archive.
* .sl8 - SIMUL8 simulation file.
* .slk - Symbolic link format file.
* .sln - Visual Studio solution object file.
* .smd - SEGA mega drive ROM file.
* .smi - RealPlayer file.
* .snd - Sound file.
* .sng - Song file.
* .snp - Microsoft Access report snapshot.
* .sol - Local Shared Object file (Flash).
* .sos - DRS OMR decode instruction file.
* .spo - SPSS output file.
* .spp - Serif PhotoPlus image file.
* .spr - Brother spreadsheet / Half-life sprite file.
* .sps - SPSS syntax file / SyncBack profile file.
* .sql - Structured Query Language file.
* .sqm - Windows Live Messenger (Software Quality Metrics) Log File / Windows Live Mail log file / Operation Flashpoint mission file.
* .srd - Supercube file.
* .srf - ATL Server file / InfoCrafter document / Raster graphics file / Raw graphics file / Spectral Response Function data / SurfSaver file / Terragen™ Surface map file.
* .srg - Self Registration File.
* .srl - Local database file / Nintendo ROM dump file.
* .srt - Subtitles file.
* .ssa - Source Safe archive file.
* .ssf - Show Shifter File.
* .ssf.00 - Show Shifter file.
* .ssf.01 - Show Shifter file.
* .sta - FinePrint stationary file.
* .stc - Open Office Calc template file.
* .std - Open Office Draw template file.
* .sti - Open Office Impress template file.
* .stm - Exchange store file / Server side include / Server side includes / State transition diagram / Media file.
* .str - String replacement file / DataPerfect file / Video game file.
* .sts - Datapulse - CIM file.
* .stw - OpenOffice Writer template file.
* .stx - Santa Barbara Instrument Group file.
* .sub - CloneCD sub channel data file.
* .suo - Visual Studio user options file.
* .sv7 - SAS data view file.
* .svg - Scalable vector graphic file.
* .svgz - Compressed scalable vector graphics file.
* .svn - Subversion directory.
* .switch - Secure package file.
* .swf - Flash file.
* .swp - Swap file.
* .sxc - Open Office Calc file.
* .sxd - Open Office Draw file.
* .sxg - Open Office master document.
* .sxi - Open Office Impress file.
* .sxm - Open Office Math file.
* .sxp - Open Office Presentation file.
* .sxw - Open Office Writer document.
* .syd - SYSTAT data file.
* .syo - SYSTAT output file.
* .sys - Windows system file.

* .tab - MapInfo table structure file.
* .tar - tape archive compressed file.
* .td - Simplex database table.
* .tex - Latex file.
* .tfw - ArcView (Tiff) world coordinates file.
* .tga - Targa bitmap.
* .tgr - Tiger line file.
* .th - Simplex database table header file.
* .thm - Video thumbnail file.
* .tif - TIFF file.
* .tiff - TIFF file.
* .tlb - Type library file.
* .tmb - Thumbnail image file.
* .tmd - Temporary file.
* .tmp - Temporary file.
* .tod - JVC video clip file.
* .topc - TopicCrunch SEO-project parameter set.
* .tp - TPwin project file.
* .tpc - 3D Topicscape inter-Topicscape topic link file.
* .tpl - Generic template file / PHP template file.
* .trb - Turbulence plugin (Animation Master).
* .tsv - Tab Separated Values file.
* .ttf - True type font.
* .tub - Paint Shop Pro picture tube file.
* .tx - TX Text Control data file.
* .txm - Text Control Demo file.
* .txt - ASCII text file.
* .ucf - User Constraint File / Coordinate list file / WebEx Universal Communications file.
* .udf - Uniqueness definition file.
* .udl - Data link file.
* .uha - UHARC compressed archive.
* .url - Internet shortcut file.
* .user - Visual Studio user options file.
* .usr - User profile file for GuildFTPD
* .utf - Ulead Video Studio subtitle file.
* .uue - UU-encoded file.
* .v01 - NT backup catalogue file.
* .v64 - Nintendo emulation ROM image.
* .vb - Visual Basic .NET source file.
* .vbproj - Visual Basic .NET project file.
* .vbs - Visual Basic script file.
* .vbx - Visual Basic extension.
* .vcf - vCard.
* .vfx - Volumetric effect plugin (Animation Master).
* .vgc - ViziGen code generation template flie.
* .vhd - Virtual Hard Disk file / Windows Server Backup virtual disk file.
* .vic - ViziGen import mappings file.
* .vip - Magix Audio Clean system project file.
* .vir - Quarantined virus file.
* .vm - Virtual memory file.
* .vmc - Microsoft Virtual PC configuration file.
* .vob - (DVD) Video Object file.
* .vpc - ViziGen code generation model control file / VIPP Project Container file.
* .vsd - Visio drawing file.
* .vsi - Visual Studio Community Content Installer file.
* .vsscc - Visual Studio Source Control Solution Root Metadata file.
* .vssscc - Visual Studio Source Control Solution Metadata file.
* .vxd - Windows 9x virtual device driver.
* .wab - Windows address book file.
* .wav - Waveform audio file.
* .wdb - Windows Works database file.
* .web - FrontPage web file.
* .wer - Windows Error Report file.
* .whb - iPod backup image file.
* .win - Microsoft Visual FoxPro save file / Pro/ENGINEER file / Opera saved session file.
* .wk1 - Lotus spreadsheet.
* .wk2 - Lotus spreadsheet.
* .wk3 - Lotus spreadsheet.
* .wk4 - Lotus spreadsheet.
* .wma - Windows Media audio file.
* .wmf - Graphics file.
* .wmv - Audio/Video file.
* .wms - Windows Media Skin definition file.
* .wmz - Windows Media Skin file.
* .wor - MapInfo workspace file.
* .wp - Word Perfect document
* .wp2 - Winplot file.
* .wp3 - Windows Photo Story project file / Winplot file.
* .wp4 - Word Perfect document.
* .wpd - WordPerfect file.
* .wpp - Web Plus Project file / WordPerfect colour palette file / Web Part Package file.
* .wps - Works word processor file.
* .wpt - Brother document / Waypoints file / WordPerfect template.
* .wrf- WebEx Recorded File.
* .wri - Windows Write Document.
* .wrl - VRML 3D file.
* .wrz - VRML 3D file.
* .wsdl - Web Services Description Language file.
* .wsdl.xml - Web Services Description Language file.
* .wsf - Script host file.
* .wsh - Script host file.
* .wsp - Web Site Publisher settings / Paint Shop Pro file / Visual C++ Workspace information file / Word Splash Pro file / Windows SharePoint Services file / Chromeleon workspace file / Whisper 32 password file.
* .wswksp - Java workspace configuration file.
* .wsz - Winamp skin.
* .wtv - Windows (recorded) TV file.
* .wvf - Waveform data file
* .wvx - Windows video playlist file.
* .x - 3d mesh file / RPC language source file.
* .xar - Vector graphics file / Excel auto-recover save file.
* .xbm - X windows cursor or bitmap.
* .xhtml - XHTML web page
* .xif - Image file / Pagis scanned document image file.
* .xlb - Microsoft Excel toolbar file.
* .xlr - Microsoft Works spreadsheet.
* .xls - Excel spreadsheet.
* .xlsx - Excel (XML) Spreadsheet file.
* .xlt - Excel template.
* .xml - Generic XML file extension.
* .xpf - Homestead SiteBuilder file.
* .xpi - Cross-Platform Installer Module.
* .xps - Microsoft (XML) Project File.
* .xrp - RationalPlan project file / Gamemaker external resources file.
* .xsd - XML schema definition file.
* .xslt - Extensible Style-sheet Language Transformation file.
* .xtf - eXtended Triton Format file.
* .xxx - Virtual PC Temporary file.
* .y - YACC source file.
* .ywf - Yeah Write! word processor file.
* .yxx - Bison source file.
* .yz - Compressed archive.
* .z1 - ZoneAlarm MailSafe quarantined file.
* .z2 - ZoneAlarm MailSafe quarantined file.
* .z3 - ZoneAlarm MailSafe quarantined file.
* .z4 - ZoneAlarm MailSafe quarantined file.
* .z5 - ZoneAlarm MailSafe quarantined file.
* .z6 - ZoneAlarm MailSafe quarantined file.
* .z7 - ZoneAlarm MailSafe quarantined file.
* .z8 - ZoneAlarm MailSafe quarantined file.
* .z80 - Sinclair Spectrum emulator file.
* .z - Unix compressed file.
* .zcat - Dell Support Center file.
* .zhp - Zipped PCL file. / SwiftView command file.
* .zip - PKzip compressed file or archive / 7-zip compressed file / other compressed file.
* .zipx - WinZip compressed file.
* .zix - WixZix compressed file / Quicken data file / Caml Light debugger file.
* .zmc - ZoneAlarm Mailsafe email file / Passport PC to Host Macro file.
* .zno - Zinio Reader Magazine file
* .zoo - Compressed archive.
* .$$$ - Temporary file.
* .~ - Outlook express address book backup.
* .~df - Backup of Delphi form file.
* .~dfm - Backup of Delphi form file.
* .~dp - Backup of Delphi project file.
* .~dpr - Backup of Delphi project file.
* .~pa - Backup of Delphi source file.
* .~pas - Backup of Delphi source file.
* .123 - Lotus 123 spreadsheet file.
* .12da - 12d Model ASCII exchange format.
* .1st - Text read-me file.
* .2gr - Windows 3.x file.
* .256 - Descent 2 palette file.
* .3dt - 3D Topicscape database file.
* .386 - Windows 3.x swap file.
* .3gr - Windows 3.x file.
* .411 - Sony Mavica data file.
* .4th - Forth language source file.
* .7z - 7-zip compressed archive file.
* .906 - Calcomp plotter file.