| Extension |
File Type |
File Description |
| .i | Developer | INTERCAL Source File |
| .i00 | Disk | DVD Shrink File Part 1 |
| .i01 | Disk | DVD Shrink File Part 2 |
| .i02 | Disk | DVD Shrink File Part 3 |
| .i5z | Data | IUCLID 5 Import/Export File |
| .iam | 3D Image | Inventor Assembly File |
| .ib | Data | InterBase Database |
| .ibp | Disk | IsoBuster Managed Image Information File |
| .ibq | Disk | IsoBuster Managed Image File |
| .ibt | Game | Texture and Model File |
| .ic1 | Image | Low Resolution Imagic Graphic |
| .ic2 | Image | Medium Resolution Imagic Graphic |
| .ic3 | Image | High Resolution Imagic Graphic |
| .ica | Image | Image Object Content Architecture (IOCA) File |
| .ica | Settings | Citrix ICA File |
| .icb | Image | Targa Bitmap Image |
| .icc | Settings | ICC Profile |
| .ice | Compressed | ICE File Archive |
| .icm | Settings | Image Color Matching Profile |
| .icn | Raster Image | Windows Icon File |
| .icns | System | Icon Resource |
| .ico | System | Icon File |
| .icon | Raster Image | Icon Image File |
| .ics | Data | iCalendar File |
| .ics | Audio | IC Recorder Sound File |
| .id | Misc | Lotus Notes User ID File |
| .idb | Developer | Visual Studio Intermediate Debug File |
| .idc | Web | Internet Database Connector File |
| .idf | Settings | MIDI Instrument Definition File |
| .idw | Image | Inventor Drawing |
| .idx | System | Index File |
| .idx | Data | HMI Historical Log Index File |
| .idx | Text | Outlook Express Mailbox Index File |
| .idx0 | Game | Runescape Cache Index File |
| .idx255 | Game | Runescape Cache File |
| .iff | Audio | Interchange File Format |
| .iff | Image | Amiga IFF Graphic |
| .ifo | Video | DVD-Video Disc Information File |
| .igc | Data | Anime List Builder Input File |
| .iges | 3D Image | Initial Graphics Exchange Specification |
| .igs | 3D Image | IGES File |
| .iif | Data | Intuit Interchange Format File |
| .iil | Text | CleanSweep Installation Log |
| .ilbm | Image | Deluxe Paint Graphic |
| .ima | Disk | Disk Image |
| .image | Disk | Apple Disk Image |
| .imapmbox | Text | IMAP Mailbox |
| .img | Disk | Macintosh Disk Image |
| .img | Disk | CloneCD Disk Image Data File |
| .imj | Image | JFIF Bitmap Image |
| .iml | Misc | ACT! Internet Mail Message |
| .imovieproj | Video | iMovie Project File |
| .imovieproject | Video | iMovie Project |
| .imy | Misc | iMelody Ringtone File |
| .in | Misc | Spyware File |
| .inc | Developer | Include File |
| .indd | Page Layout | Adobe InDesign File |
| .indt | Text | InDesign Template |
| .inetloc | Misc | Internet Location |
| .inf | Settings | Setup File or Installer Script |
| .info | Raster Image | ZoomBrowser Image Index File |
| .ing | Misc | MasterCook Ingredients File |
| .ini | System | Initialization File |
| .ini | Settings | Gravis UltraSound Bank Setup File |
| .ini | Settings | Symbian OS Configuration File |
| .ink | Image | Pantone Reference File |
| .ink | Data | Mimio Ink Data File |
| .ink | Vector Image | Pocket PC Handwritten Note |
| .inm | Misc | FaxMaster Document |
| .inp | Data | ABAQUS Input File |
| .ins | System | Internet Naming Service File |
| .ins | Audio | Ensoniq Instrument |
| .ins | Audio | Sample Cell II Instrument Definition File |
| .inx | Executable | Compiled Script |
| .inx | Page Layout | InDesign Interchange File |
| .ion | System | 4DOS File Description |
| .ipf | Executable | SMS Installer Script |
| .ipf | Text | OS/2 Help File |
| .ipf | Disk | Interchangeable Preservation File |
| .ipg | Compressed | iPod Game File |
| .ipk | Compressed | Itsy Package |
| .ips | Game | Internal Patching System Patch File |
| .ipsw | Misc | iPod and iPhone Software Update File |
| .ipt | 3D Image | Inventor Part File |
| .iqy | Web | Internet Query |
| .irock | Data | intelliRock Sensor Data File |
| .isc | Developer | Xilinx Device Configuration File |
| .isf | Data | Inspiration Flowchart Document |
| .ish | Compressed | ISH Compressed Archive |
| .isn | Misc | Installer Source Files |
| .iso | Disk | Disc Image File |
| .isp | Settings | IIS Internet Service Provider Settings |
| .isr | Game | GoMoku Game File |
| .iss | Developer | InstallShield Silent Response |
| .isu | Executable | InstallShield Uninstaller Script |
| .isz | Disk | Zipped ISO Disk Image |
| .it | Audio | Impulse Tracker Module |
| .itc | Misc | iTunes Cover Flow Data File |
| .ithmb | Image | iPod Photo Thumbnails |
| .iti | Audio | Impulse Tracker Instrument |
| .itl | Data | iTunes Library File |
| .itn | Data | TomTom Navigator Itinerary File |
| .its | System | Internet Document Set |
| .its | Audio | Impulse Tracker Sample |
| .itw | Data | InTouch With Database File |
| .itx | Data | ITX Form Template |
| .iv2i | Backup | Norton Ghost Incremental Virtual Volume Image |
| .iva | Misc | Dementia.4207 Virus File |
| .ivf | Video | Indeo Video Format File |
| .ivr | Image | Image World |
| .ivs | Video | Internet Streaming Video |
| .ivt | Data | Beyond 20/20 Table |
| .iwd | Game | Call of Duty 2 Game Data File |
| .iws | Misc | InstallWatch Scan File |
| .ixa | Disk | Ulead Disc Image format |
| .izz | Video | Isadora Media Control Project |
| .izzy | Video | Isadora Project |
