A file extension or file name extension is the ending of a file that helps identify the type of file in operating systems, such as Microsoft Windows. In Microsoft Windows, the file name extension is a period that is often followed by three characters but may also be one, two, or four characters long. Here we listed out some of the basic File extensions.
| Data Files | |
| .CSV | Comma Separated Values File |
| .DAT | Data File |
| .GED | GEDCOM Genealogy Data File |
| .KEY | Keynote Presentation |
| .KEYCHAIN | Mac OS X Keychain File |
| .PPS | PowerPoint Slide Show |
| .PPT | PowerPoint Presentation |
| .PPTX | PowerPoint Open XML Presentation |
| .SDF | Standard Data File |
| .TAR | Consolidated Unix File Archive |
| .TAX2016 | TurboTax 2016 Tax Return |
| .TAX2017 | TurboTax 2017 Tax Return |
| .VCF | vCard File |
| .XML | XML File |
| Text Files | |
| .DOC | Microsoft Word Document |
| .DOCX | Microsoft Word Open XML Document |
| .LOG | Log File |
| .MSG | Outlook Mail Message |
| .ODT | OpenDocument Text Document |
| .PAGES | Pages Document |
| .RTF | Rich Text Format File |
| .TEX | LaTeX Source Document |
| .TXT | Plain Text File |
| .WPD | WordPerfect Document |
| .WPS | Microsoft Works Word Processor Document |
| Audio Files | |
| .AIF | Audio Interchange File Format |
| .IFF | Interchange File Format |
| .M3U | Media Playlist File |
| .M4A | MPEG-4 Audio File |
| .MID | MIDI File |
| .MP3 | MP3 Audio File |
| .MPA | MPEG-2 Audio File |
| .WAV | WAVE Audio File |
| .WMA | Windows Media Audio File |
| Video Files | |
| .3G2 | 3GPP2 Multimedia File |
| .3GP | 3GPP Multimedia File |
| .ASF | Advanced Systems Format File |
| .AVI | Audio Video Interleave File |
| .FLV | Animate Video File |
| .M4V | iTunes Video File |
| .MOV | Apple QuickTime Movie |
| .MP4 | MPEG-4 Video File |
| .MPG | MPEG Video File |
| .RM | RealMedia File |
| .SRT | SubRip Subtitle File |
| .SWF | Shockwave Flash Movie |
| .VOB | DVD Video Object File |
| .WMV | Windows Media Video File |
| 3D Image Files | |
| .3DM | Rhino 3D Model |
| .3DS | 3D Studio Scene |
| .MAX | 3ds Max Scene File |
| .OBJ | Wavefront 3D Object File |
| Raster Image Files | |
| .BMP | Bitmap Image File |
| .DDS | DirectDraw Surface |
| .GIF | Graphical Interchange Format File |
| .JPG | JPEG Image |
| .PNG | Portable Network Graphic |
| .PSD | Adobe Photoshop Document |
| .PSPIMAGE | PaintShop Pro Image |
| .TGA | Targa Graphic |
| .THM | Thumbnail Image File |
| .TIF | Tagged Image File |
| .TIFF | Tagged Image File Format |
| .YUV | YUV Encoded Image File |
| Vector Image Files | |
| .AI | Adobe Illustrator File |
| .EPS | Encapsulated PostScript File |
| .PS | PostScript File |
| .SVG | Scalable Vector Graphics File |
| Page Layout Files | |
| .INDD | Adobe InDesign Document |
| .PCT | Picture File |
| Portable Document Format File | |
| Spreadsheet Files | |
| .XLR | Works Spreadsheet |
| .XLS | Excel Spreadsheet |
| .XLSX | Microsoft Excel Open XML Spreadsheet |
| Database Files | |
| .ACCDB | Access 2007 Database File |
| .DB | Database File |
| .DBF | Database File |
| .MDB | Microsoft Access Database |
| .PDB | Program Database |
| .SQL | Structured Query Language Data File |
| Executable Files | |
| .APK | Android Package File |
| .APP | Mac OS X Application |
| .BAT | DOS Batch File |
| .CGI | Common Gateway Interface Script |
| .COM | DOS Command File |
| .EXE | Windows Executable File |
| .GADGET | Windows Gadget |
| .JAR | Java Archive File |
| .WSF | Windows Script File |
| Game Files | |
| .B | Grand Theft Auto 3 Saved Game File |
| .DEM | Video Game Demo File |
| .GAM | Saved Game File |
| .NES | Nintendo (NES) ROM File |
| .ROM | N64 Game ROM File |
| .SAV | Saved Game |
| CAD Files | |
| .DWG | AutoCAD Drawing Database File |
| .DXF | Drawing Exchange Format File |
| GIS Files | |
| .GPX | GPS Exchange File |
| .KML | Keyhole Markup Language File |
| .KMZ | Google Earth Placemark File |
| Web Files | |
| .ASP | Active Server Page |
| .ASPX | Active Server Page Extended File |
| .CER | Internet Security Certificate |
| .CFM | ColdFusion Markup File |
| .CSR | Certificate Signing Request File |
| .CSS | Cascading Style Sheet |
| .DCR | Shockwave Media File |
| .HTM | Hypertext Markup Language File |
| .HTML | Hypertext Markup Language File |
| .JS | JavaScript File |
| .JSP | Java Server Page |
| .PHP | PHP Source Code File |
| .RSS | Rich Site Summary |
| .XHTML | Extensible Hypertext Markup Language File |
| Plugin Files | |
| .CRX | Chrome Extension |
| .PLUGIN | Mac OS X Plugin |
| Font Files | |
| .FNT | Windows Font File |
| .FON | Generic Font File |
| .OTF | OpenType Font |
| .TTF | TrueType Font |
| System Files | |
| .CAB | Windows Cabinet File |
| .CPL | Windows Control Panel Item |
| .CUR | Windows Cursor |
| .DESKTHEMEPACK | Windows 8 Desktop Theme Pack File |
| .DLL | Dynamic Link Library |
| .DMP | Windows Memory Dump |
| .DRV | Device Driver |
| .ICNS | Mac OS X Icon Resource File |
| .ICO | Icon File |
| .LNK | Windows File Shortcut |
| .SYS | Windows System File |
| Settings Files | |
| .CFG | Configuration File |
| .INI | Windows Initialization File |
| .PRF | Outlook Profile File |
| Encoded Files | |
| .HQX | BinHex 4.0 Encoded File |
| .MIM | Multi-Purpose Internet Mail Message File |
| .UUE | Uuencoded File |
| Compressed Files | |
| .7Z | 7-Zip Compressed File |
| .CBR | Comic Book RAR Archive |
| .DEB | Debian Software Package |
| .GZ | Gnu Zipped Archive |
| .PKG | Mac OS X Installer Package |
| .RAR | WinRAR Compressed Archive |
| .RPM | Red Hat Package Manager File |
| .SITX | StuffIt X Archive |
| .TAR.GZ | Compressed Tarball File |
| .ZIP | Zipped File |
| .ZIPX | Extended Zip File |
| Disk Image Files | |
| .BIN | Binary Disc Image |
| .CUE | Cue Sheet File |
| .DMG | Mac OS X Disk Image |
| .ISO | Disc Image File |
| .MDF | Media Disc Image File |
| .TOAST | Toast Disc Image |
| .VCD | Virtual CD |
| Developer Files | |
| .C | C/C++ Source Code File |
| .CLASS | Java Class File |
| .CPP | C++ Source Code File |
| .CS | C# Source Code File |
| .DTD | Document Type Definition File |
| .FLA | Adobe Animate Animation |
| .H | C/C++/Objective-C Header File |
| .JAVA | Java Source Code File |
| .LUA | Lua Source File |
| .M | Objective-C Implementation File |
| .PL | Perl Script |
| .PY | Python Script |
| .SH | Bash Shell Script |
| .SLN | Visual Studio Solution File |
| .SWIFT | Swift Source Code File |
| .VB | Visual Basic Project Item File |
| .VCXPROJ | Visual C++ Project |
| .XCODEPROJ | Xcode Project |
| Backup Files | |
| .BAK | Backup File |
| .TMP | Temporary File |
| Misc Files | |
| .CRDOWNLOAD | Chrome Partially Downloaded File |
| .ICS | Calendar File |
| .MSI | Windows Installer Package |
| .PART | Partially Downloaded File |
| .TORRENT | BitTorrent File |
