| I File Extensions |
File types with extensions that start with the letter I.
| Extension | File Type | File Summary |
| .i | Manufacturer | Visual Studio Intermediate File |
| .i | Manufacturer | INTERCAL Source File |
| .i00 | Disk Image | DVD Shrink Part 1 File |
| .i01 | Disk Image | DVD Shrink Part 2 File |
| .i02 | Disk Image | DVD Shrink Part 3 File |
| .i5z | Data | IUCLID 5 Import/Export File |
| .iaf | Settings | Outlook Internet Account File |
| .iam | CAD | Inventor Assembly File |
| .ib | Database | InterBase Database |
| .ibcd | Data | InstantBingoCard Document |
| .ibp | Disk Image | IsoBuster Managed Image Information File |
| .ibplugin | Plugin | Interface Builder Plug-in |
| .ibq | Disk Image | IsoBuster Managed Image File |
| .ibt | Game | Texture and Model File |
| .ic1 | Raster Image | Low Resolution Imagic Graphics File |
| .ic2 | Raster Image | Medium Resolution Imagic Graphics File |
| .ic3 | Raster Image | High Resolution Imagic Graphics File |
| .ica | Raster Image | Image Object Content Architecture File |
| .ica | Settings | Citrix ICA File |
| .icalevent | Data | iCal Event File |
| .icaltodo | Data | iCal To Do File |
| .icap | Page Layout | InCopy Package File |
| .icb | Raster Image | Targa ICB Bitmap Image |
| .icbu | Backup | iCal Backup File |
| .icc | Settings | ICC Profile |
| .icd | Executable | SafeDisc Encrypted Program |
| .icd | Settings | Installable Client Driver File |
| .ice | Compressed | ICE File Archive |
| .icl | System | Windows Icon Library File |
| .icm | Settings | Image Color Matching Profile |
| .icma | Misc | InCopy Assignment File |
| .icml | Page Layout | InCopy Document |
| .icn | Raster Image | Windows Icon File |
| .icns | System | Mac OS X Icon Resource File |
| .ico | System | Icon File |
| .icon | Raster Image | Icon Image File |
| .iconpackage | Settings | IconPackager Theme File |
| .icontainer | Misc | CandyBar iContainer File |
| .ics | CAD | IronCAD 3D Drawing File |
| .ics | Audio | IC Recorder Sound File |
| .ics | Data | iCalendar File |
| .icursorfx | Settings | iCursor Effect File |
| .id | Misc | Lotus Notes User ID File |
| .id2 | Data | Windows Live Messenger Emoticon File |
| .idap | Page Layout | Adobe InDesign Assignment Package |
| .idb | Manufacturer | Visual Studio Intermediate Debug File |
| .idc | Web | Internet Database Connector File |
| .idf | Settings | MIDI Instrument Definition File |
| .idl | Manufacturer | Interface Definition Language File |
| .idlk | Misc | Adobe InDesign Lock File |
| .idml | Page Layout | Adobe InDesign Markup Language File |
| .idms | Page Layout | Adobe InDesign Snippet |
| .idpk | Page Layout | Adobe InDesign Package for GoLive File |
| .idpp | Settings | Adobe InDesign Preflight Profile |
| .idw | CAD | Inventor Drawing |
| .idx | System | Index File |
| .idx | Misc | Movie Subtitle File |
| .idx | Data | HMI Historical Log Index File |
| .idx | Data | Navigation POI File |
| .idx | Text | Outlook Express Mailbox Index File |
| .idx0 | Game | Runescape Cache Index File |
| .idx255 | Game | Runescape Cache File |
| .ies | Data | IES Photometric Data File |
| .if | CAD | Procedimientos-Uno IFWin Project File |
| .ifc | 3D Image | Industry Foundation Classes File |
| .iff | Audio | Interchange File Format |
| .ifo | Video | DVD-Video Disc Information File |
| .igc | Data | Anime List Builder Input File |
| .iges | 3D Image | IGES File |
| .igr | Settings | Quest3D Channel Group Layout File |
| .igs | CAD | IGES Drawing File |
| .ihw | Settings | IN-HEH Timeline Workspace |
| .ihx | Database | IN-HEH Timeline Database |
| .ii | Data | IconWorkshop Extended Information File |
| .iif | Data | Intuit Interchange Format File |
| .iil | Text | CleanSweep Installation Log |
| .iim | Executable | iMacro Macro File |
| .iip | Settings | ThinAnywhere Configuration File |
| .iip | Settings | Install Creator Pro Settings File |
| .iit | Settings | Install Creator Settings File |
| .iix | Misc | Translation Memory Index File |
| .ilbm | Raster Image | Interleaved Bitmap Image |
| .ildoc | Page Layout | QuickSilver Document |
| .ima | Disk Image | Disk Image |
| .image | Disk Image | Apple Disk Image |
| .imapmbox | Text | IMAP Mailbox |
| .imf | Audio | Id Music File |
| .img | GIS | Garmin Map File |
| .img | Raster Image | GEM Image |
| .img | GIS | ERDAS IMAGINE Image File |
| .img | Disk Image | Floppy Disk Image |
| .img | Disk Image | Macintosh Disk Image |
| .img | Disk Image | CloneCD Disk Image Data File |
| .imga | Game | Aleph One Image File |
| .imi | GIS | Magellan Map File |
| .imj | Raster Image | JFIF Bitmap Image |
| .iml | Manufacturer | IntelliJ IDEA Module |
| .iml | Misc | ACT! Internet Mail Message |
| .imovieproj | Video | iMovie Project File |
| .imovieproject | Video | iMovie Project |
| .imp | Audio | Audition Impulse File |
| .imt | Data | My Time Data File |
| .imy | Misc | iMelody Ringtone File |
| .in | Misc | Spyware File |
| .inc | Manufacturer | Include File |
| .inca | Misc | InCopy CS3 Assignment File |
| .incd | Page Layout | InCopy Document |
| .incp | Data | InCopy CS3 Package File |
| .inct | Page Layout | InCopy Template |
| .incx | Page Layout | InCopy CS3 Interchange File |
| .ind | Page Layout | Adobe InDesign Document |
| .ind | Misc | Memory Stick Formatting File |
| .indb | Page Layout | Adobe InDesign Book File |
| .indd | Page Layout | Adobe InDesign Document |
| .indk | Misc | Adobe InDesign Shortcut Set File |
| .indl | Page Layout | Adobe InDesign Library |
| .indp | Page Layout | Adobe InDesign CS3 Package File |
| .inds | Page Layout | Adobe InDesign Snippet File |
| .indt | Page Layout | Adobe InDesign Template |
| .inetloc | Misc | Internet Location |
| .inf | Settings | Setup Information File |
| .info | Raster Image | ZoomBrowser Image Index File |
| .info | Misc | Generic Information File |
| .info | Misc | Texinfo Document |
| .ing | Misc | MasterCook Ingredients File |
| .ini | Settings | Symbian OS Configuration File |
| .ini | Settings | Windows Initialization File |
| .ini | Settings | Gravis UltraSound Bank Setup File |
| .ink | Vector Image | Pocket PC Handwritten Note |
| .ink | Data | Mimio Ink Data File |
| .ink | Vector Image | InkML Image |
| .ink | Raster Image | Pantone Reference File |
| .inl | Manufacturer | C++ Inline File |
| .inlk | Misc | Adobe InDesign Lock File |
| .inm | Misc | FaxMaster Document |
| .inms | Settings | Adobe InDesign Menu Set File |
| .inp | Data | ABAQUS Input File |
| .inp | Game | MAME Replay File |
| .ins | System | Internet Naming Service File |
| .ins | Audio | Ensoniq Instrument |
| .ins | Audio | Sample Cell II Instrument Definition File |
| .ins | Data | Inspiration File |
| .int | Raster Image | SGI Integer Image |
| .inv | Game | INVedit File |
| .inx | Executable | Compiled Script |
| .inx | Page Layout | Adobe InDesign Interchange File |
| .inx | Plugin | Inkscape Extension Descriptor File |
| .ion | System | 4DOS File Description |
| .ip | Data | IconPackager Theme File |
| .ipa | Executable | iPhone or iPod Touch Application |
| .ipd | Backup | BlackBerry Backup File |
| .ipf | Disk Image | Interchangeable Preservation File |
| .ipf | CAD | iMPACT Project File |
| .ipf | Executable | SMS Installer Script |
| .ipf | Text | OS/2 Help File |
| .ipg | Compressed | iPod Game File |
| .ipk | Compressed | Itsy Package |
| .ipmeta | Data | Apple iPhoto Metadata File |
| .ipn | CAD | Inventor Presentation File |
| .ipp | Manufacturer | Inline Guard Macro File |
| .ipr | Manufacturer | IntelliJ IDEA Project File |
| .ipr | Manufacturer | InstallShield Professional Project File |
| .iproject | Data | iClone Project File |
| .ips | Game | Internal Patching System Patch File |
| .ipsw | Misc | iPod and iPhone Software Update File |
| .ipt | CAD | Inventor Part File |
| .iptheme | Settings | IconPackager Raw Theme File |
| .ipx | Raster Image | IPIX Image |
| .iqy | Web | Internet Query |
| .irock | Data | intelliRock Sensor Data File |
| .iros | Settings | Adobe Save For Web Settings File |
| .irp | Data | Internet Researcher Project File |
| .irr | Data | Brewer Lamp File |
| .irs | Settings | Adobe Save For Web Settings |
| .irx | Data | Brewer Irradiation File |
| .is1 | Data | M3 Sakura Real-Time Save 1 File |
| .is1 | Data | Synergy/DE Data Index File |
| .isc | Manufacturer | Xilinx Device Configuration File |
| .isd | Page Layout | Flexera InstallShield Dialog Box File |
| .ise | Manufacturer | InstallShield Express Project File |
| .isf | Data | Inspiration Flowchart Document |
| .ish | Compressed | ISH Compressed Archive |
| .ish1 | Data | Animation-ish Wiggledoodle-ish Document |
| .ish2 | Data | Animation-ish FlipBook-ish Document |
| .ish3 | Data | Animation-ish Advanced-ish Document |
| .ism | Manufacturer | InstallShield Project File |
| .isn | Misc | Installer Source Files |
| .iso | Disk Image | Disc Image File |
| .isp | Settings | IIS Internet Service Provider Settings |
| .isr | Game | GoMoku Game File |
| .iss | Settings | Inno Setup Script |
| .iss | Settings | InstallShield Silent Response File |
| .ist | Data | Inspiration Template |
| .ist | Manufacturer | InstallShield Project Template File |
| .isu | Executable | InstallShield Uninstaller Script |
| .isz | Disk Image | Zipped ISO Disk Image |
| .it | Audio | Impulse Tracker Module |
| .ita | Compressed | IconTweaker Theme Archive |
| .itc | Misc | iTunes Cover Flow Data File |
| .itc2 | Raster Image | iTunes Cover Flow Data File 2 |
| .itdb | Database | iTunes Database File |
| .ite | Data | iTunes Extras File |
| .ithmb | Raster Image | iPod and iPhone Photo Thumbnails File |
| .iti | Audio | Impulse Tracker Instrument |
| .itl | Data | iTunes Library File |
| .itlp | Data | iTunes LP Album File |
| .itm | Data | iThink Model File |
| .itms | Web | iTunes Music Store Link File |
| .itn | Data | TomTom Navigator Itinerary File |
| .itpc | Web | iTunes Podcast Link File |
| .its | System | Internet Document Set |
| .its | Audio | Impulse Tracker Sample |
| .itt | Settings | IconTweaker Theme File |
| .itw | Database | InTouch With Database File |
| .itx | Data | ITX Form Template |
| .iup | Data | Fritz Update File |
| .iv | 3D Image | Open Inventor Scene Graph File |
| .iv2i | Backup | Norton Ghost Incremental Virtual Volume Image |
| .iva | Misc | Dementia.4207 Virus File |
| .iva | Video | Surveillance Video File |
| .ivc | Data | InteliSea Vessel Configuration File |
| .ive | 3D Image | OpenSceneGraph Binary File |
| .ivf | Video | Indeo Video Format File |
| .ivr | Raster Image | Image Worlds File |
| .ivr | Video | Internet Video Recording |
| .ivs | Video | Internet Streaming Video |
| .ivt | Data | Beyond 20/20 Table |
| .ivt | Game | International Volleyball 2006 Data File |
| .iw | Data | Chain Engineering Database File |
| .iwd | Game | Call of Duty Game Data File |
| .iws | Manufacturer | IntelliJ IDEA Web Page |
| .iws | Misc | InstallWatch Scan File |
| .iwz | Manufacturer | InstallShield Express 2 Project File |
| .ix | Settings | dtSearch Index File |
| .ix2 | Data | WordPerfect Address Book File |
| .ixa | Disk Image | Ulead Disc Image format |
| .ixb | Data | Ulead Disc Image |
| .izz | Video | Isadora Media Control Project |
| .izzy | Video | Isadora Project |