File extensions start with character 'D'
| File Type | Category | File Format | |
|---|---|---|---|
| .d00 | Disk Image Files | VirtualDrive Disc Image Part File | |
| .d01 | Data Files | VirtualDrive Disc Image Part 2 File | |
| .d3dbsp | Map Files | Call of Duty Map File | |
| .da2 | Data Files | DeepAnalysis Save File | |
| .daa | Archive Files | PowerISO Direct-Access-Archive | |
| .dae | 3D Files | Digital Asset Exchange File | |
| .daf | Data Files | Digital Anchor File | |
| .dal | Partially Downloaded Files | Download Accelerator Plus URL List | |
| .dam | Data Files | DeltaMaster Analysis Model | |
| .dap | Microsoft Files | Access Data Access Page | |
| .das | Data Files | DeltaMaster Analysis Session | |
| .dat | Data Files | Data File | |
| .dat_old | Game Files | Minecraft Level.dat Backup File | |
| .data | Apple Files | Analysis Studio Offline Data File | |
| .dav | Digital Video Files | DVR365 Video File | |
| .db | Database Files | Database File | |
| .db- | Data Files | Norton Nprotect Database File | |
| .db-shm | Android Files | SQLite Database Shared Memory File | |
| .db-wal | Android Files | SQLite Database Write-Ahead Log File | |
| .db3 | Database Files | SQLite Database File | |
| .dba | Backup Files | Palm Datebook Backup File | |
| .dbc | Database Files | FoxPro Database | |
| .dbd | Data Files | DemoShield Project | |
| .dbf | Database Files | Database File | |
| .dbg | Configuration Files | FoxPro Debugger Configuration | |
| .dbgsym | Data Files | Debug Symbols File | |
| .dbk | Backup Files | Sony Ericsson Mobile Phone Backup File | |
| .dbm | Project Files | ColdFusion Server File | |
| .dbo | Development Files | DarkBASIC Object | |
| .dbs | Database Files | SQLBase Database File | |
| .dbx | Multiple Use Files | Outlook Express E-mail Folder | |
| .dcf | Audio Files | DRM Content Format File | |
| .dck | Digital Video Files | Resolume Deck File | |
| .dcl | Configuration Files | AutoCAD Dialog Definition File | |
| .dcm | Raster Graphics Files | DICOM Image | |
| .dcmd | Data Files | DiskCatalogMaker Thumbnail-Enabled Catalog | |
| .dcmf | Data Files | DiskCatalogMaker Catalog | |
| .dcpf | Data Files | Disc Copier Project File | |
| .dcpr | Data Files | Adobe DNG Camera Profile Recipe File | |
| .dcr | Camera Photo Files | Kodak RAW Image File | |
| .dcs | Vector Graphics Files | Desktop Color Separation File | |
| .dct | Partially Downloaded Files | Dictionary File | |
| .ddb | Data Files | Digidesign Database | |
| .ddc | Data Files | DivX Descriptor File | |
| .ddcx | Data Files | DivX Descriptor 2 File | |
| .ddd | Adobe Files | GLBasic 3D Data File | |
| .dds | Raster Graphics Files | DirectDraw Surface | |
| .ddt | Game Files | Football Manager Keep Player Data File | |
| .deb | Package Files | Debian Software Package | |
| .decrypt | Multiple Use Files | Decrypted Microsoft ESD File | |
| .def | Development Files | Module-Definition File | |
| .dem | Game Files | Video Game Demo File | |
| .des | 3D Graphics Files | Corel Designer File | |
| .design | Vector Graphics Files | Microsoft Expression Design Drawing | |
| .deskthemepack | Windows System Files | Windows 8 Desktop Theme Pack File | |
| .desktop | Partially Downloaded Files | Desktop Entry File | |
| .dewf | Audio Files | SoundEdit Recorded Instrument | |
| .dex | Development Files | Dalvik Executable File | |
| .df2 | Audio Files | Defractor 2 Instrument | |
| .dfc | Audio Files | Defractor Instrument | |
| .dff | Game Files | RenderWare Model File | |
| .dfm | Development Files | Delphi Form | |
| .dfproj | Data Files | DVD Flick Project | |
| .dgc | Turbo Tax Files | DGCA File Archive | |
| .dgk | CAD Files | Delcam 3D Model File | |
| .dgn | CAD Files | MicroStation Design File | |
| .dgs | Text Files | Dagesh Pro Document | |
| .dhcd | Data Files | DHCD Computing Application Data File | |
| .dhs | Vector Graphics Files | HyperSnap Drawing | |
| .dia | Vector Graphics Files | Dia Diagram File | |
| .diagcab | System Files | Troubleshooting Pack Cabinet File | |
| .diagpkg | System Files | Troubleshooting Pack File | |
| .dif | Data Files | Data Interchange Format | |
| .dig | Audio Files | Sound Designer Audio File | |
| .dii | Data Files | Summation Batch Load File | |
| .dir | Digital Video Files | Adobe Director Movie | |
| .disk | Disk Image Files | Linux Virtual Hard Disk | |
| .diskdefines | Multiple Use Files | Linux LiveCD Information File | |
| .dist | Apple Files | Mac OS X Distribution Script | |
| .dita | Data Files | DITA Document | |
| .ditamap | Data Files | DITA Topic Map File | |
| .ditaval | Data Files | DITA Conditions File | |
| .divx | Digital Video Files | DivX-Encoded Movie File | |
| .diz | Description Files | Description in Zip File | |
| .djm | Data Files | Dynojet Map File | |
| .djvu | Raster Graphics Files | DjVu Image | |
| .dl_ | Compressed Files | Compressed DLL File | |
| .dlc | Database Files | Download Link Container File | |
| .dlg | GIS Files | Digital Line Graph | |
| .dll | Dynamic Link Library Files | Dynamic Link Library | |
| .dls | Audio Files | Downloadable Sounds File | |
| .dm | Audio Files | DRM Delivery Message | |
| .dm1 | Development Files | ER/Studio Data Model File | |
| .dm2 | Data Files | Toad Data Modeler 2 File | |
| .dmc | Data Files | Datamartist Data Canvas File | |
| .dmd | Development Files | SQL Developer Data Modeler File | |
| .dmf | Audio Files | Delusion Digital Music File | |
| .dmg | Apple Files | Mac OS X Disk Image | |
| .dmo | Game Files | Duke Nukem 3D Demo File | |
| .dmp | Windows System Files | Windows Memory Dump | |
| .dms | Disk Image Files | Disk Masher Image | |
| .dmsa | Audio Files | Music Disc Creator Project File | |
| .dmse | Audio Files | Sound Editor Project File | |
| .dmsk | Data Files | DivX Temporary Video Data File | |
| .dmsp | Data Files | PhotoSuite Project File | |
| .dna | Backup Files | CA Backup and Migration Backup File | |
| .dne | Text Files | Netica Text File | |
| .dnl | Database Files | DNAML eBook File | |
| .do | Microsoft Files | Java Servlet | |
| .doc | Microsoft Office Files | Microsoft Word Document | |
| .dockzip | Data Files | ObjectDock File | |
| .docm | Microsoft Office Files | Word Open XML Macro-Enabled Document | |
| .docset | Development Files | Doxygen Document Set File | |
| .docx | Microsoft Office Files | Microsoft Word Open XML Document | |
| .docz | Text Files | ThinkFree Online Note Document | |
| .dot | Page Layout Files | Word Document Template | |
| .dotm | Text Files | Word Open XML Macro-Enabled Document Template | |
| .dotx | Microsoft Office Files | Word Open XML Document Template | |
| .downloading | Multiple Use Files | Pando Incomplete Download File | |
| .dox | Text Files | MultiMate Document | |
| .dpa | Video Files | DrawPlus Animation File | |
| .dpb | Backup Files | DataPilot Backup File | |
| .dpk | Development Files | Delphi Package | |
| .dpm | Plug-in Files | Pro Tools Plugin File | |
| .dpn | Data Files | Depiction Data File | |
| .dpr | Development Files | Delphi Project | |
| .dps | Skin Files | Kingsoft Presentation File | |
| .dpt | Data Files | Kingsoft Presentation Template | |
| .dpx | Raster Graphics Files | Digital Picture Exchange File | |
| .dqy | Microsoft Office Files | Excel Query File | |
| .dra | Audio Files | Nuance Dragon Voice Recording File | |
| .drf | 3D Graphics Files | VIZ Render File | |
| .drg | CAD Drawing Files | I-Doser Audio Drug File | |
| .drl | Data Files | Gerber Drill Rack File | |
| .drm | Configuration Files | Cubase Drum Map File | |
| .drwdot | CAD Files | SolidWorks Drawing Template | |
| .ds2 | Audio Files | Olympus DSS Pro Audio File | |
| .ds_store | Configuration Files | Mac OS X Folder Settings File | |
| .dsb | Data Files | Wondershare DVD Slideshow Builder Project | |
| .dsb | Backup Files | Dell DataSafe Backup File | |
| .dsc | Multiple Use Files | Nikon Disk Identification File | |
| .dsd | Configuration Files | AutoCAD Drawing Set Description File | |
| .dsf | Graphics Files | DAZ Studio Asset File | |
| .dsf | Vector Graphics Files | Designer File | |
| .dsk | Disk Image Files | Disk Image | |
| .dsm | Audio Files | Digital Sound Module | |
| .dsn | Microsoft Files | Database Source Name File | |
| .dsp | Development Files | Visual C++ 6 Project | |
| .dss | Audio Files | Digital Speech Standard File | |
| .dsv | Microsoft Files | DeSmuME Save File | |
| .dsx | Graphics Files | Diet Studio XML File | |
| .dsy | Data Files | Directory Synchronizer Project File | |
| .dsz | Data Files | Orchida (OES) Embroidery File | |
| .dta | Data Files | Chain Engineering Database | |
| .dtd | Development Files | Document Type Definition File | |
| .dtf | Partially Downloaded Files | Domino Temporary File | |
| .dtm | Audio Files | DigiTrakker Module | |
| .dtr | Data Files | DATroniC Data Recording | |
| .dts | Data Transformation Files | DTS Encoded Audio File | |
| .dtshd | Audio Files | DTS-HD Master Audio File | |
| .dtsx | Database Files | DTS Settings File | |
| .dv4 | Digital Video Files | Bosch Security Systems CCTV Video File | |
| .dvd | Disk Image Files | CloneCD DVD Information File | |
| .dvdproj | Data Files | iDVD Project File | |
| .dvds | Data Files | DVDStyler Project File | |
| .dvf | Audio Files | Sony Digital Voice File | |
| .dvi | Text Files | Device Independent Format File | |
| .dvr | Digital Video Files | Microsoft Recorded TV Show | |
| .dwc | Partially Downloaded Files | Emulex DWC Firmware Update File | |
| .dwd | Audio Files | DiamondWare Digital Audio File | |
| .dwf | Autodesk Files | Design Web Format File | |
| .dwfx | CAD Files | Design Web Format XPS File | |
| .dwg | CAD Files | AutoCAD Drawing Database File | |
| .dwi | Data Files | Dance With Intensity Song File | |
| .dwp | Data Files | DarkWave Studio Project File | |
| .dws | CAD Files | AutoCAD Drawing Standards File | |
| .dwz | Data Files | DVD MovieFactory Project File | |
| .dx | Text Files | DEC WPS Plus File | |
| .dxf | CAD Files | Drawing Exchange Format File | |
| .dz | Data Files | Dzip File | |
| .dzp | Video Files | DirectorZone Particle Effect File |