I File Extensions
File extensions that start with the letter
I
| Extension | File Type | File Description |
| .ib | Data | InterBase Database |
| .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 |
| .icb | Image | Targa Bitmap Image |
| .icn | Image | Windows Icon |
| .icns | System | Icon Resource |
| .ico | System | Icon File |
| .ics | Data | iCalendar File |
| .idf | Text | MIDI Instrument Definition File |
| .idw | Image | Inventor Drawing |
| .idx | System | Index File |
| .iff | Audio | Interchangeable File Format |
| .ifo | Video | DVD-Video Disc Information |
| .iges | Image | Initial Graphics Exchange Specification |
| .igs | Image | Initial Graphics Exchange Specification |
| .iil | Text | CleanSweep Installation Log |
| .ilbm | Image | Deluxe Paint Graphic |
| .ima | Disk | Disk Image |
| .image | Disk | Apple Disk Image |
| .img | Disk | Macintosh Disk Image |
| .imj | Image | JFIF Bitmap Image |
| .iml | Misc | ACT! Internet Mail Message |
| .inc | Developer | Include File |
| .indd | Image | Adobe InDesign File |
| .inf | System | Setup File or Installer Script |
| .ini | System | Initialization File |
| .ink | Image | Pantone Reference File |
| .inm | Misc | FaxMaster Document |
| .inp | Data | ABAQUS Input File |
| .ins | System | Internet Naming Service |
| .inx | Executable | Compiled Script |
| .ion | System | 4DOS File Description |
| .ipf | Executable | SMS Installer Script |
| .ipf | Text | OS/2 Help File |
| .iqy | Web | Internet Query |
| .ish | Compressed | ISH Compressed Archive |
| .isn | Misc | Installer Source Files |
| .iso | Disk | Disc Image |
| .isp | System | IIS Internet Service Provider Settings |
| .iss | Developer | InstallShield Silent Response |
| .it | Audio | Impulse Tracker Module |
| .ithmb | Image | iPod Photo Thumbnails |
| .its | System | Internet Document Set |
| .iva | Misc | Dementia.4207 Virus File |
| .ivf | Video | Intel Video Format |
| .ivr | Image | Image World |
| .ivs | Video | Internet Streaming Video |
| .ivt | Data | Beyond 20/20 Table |
| .iws | Misc | InstallWatch Scan File |
| .izz | Video | Isadora Patch |