| Extension |
File Type |
File Description |
| .k25 | Audio | Kurzweil K2500 File |
| .k26 | Audio | Kurzweil K2600 File |
| .kar | Audio | Karaoke MIDI File |
| .kb | Developer | C++ Keyboard Script |
| .kbd | System | Keyboard Layout Script |
| .kdb | Data | Keypass Database File |
| .kdc | Raster Image | Kodak Photo-Enhancer File |
| .kdevdlg | Developer | KDevelop Dialog Box File |
| .kdevelop | Developer | KDevelop Project Data File |
| .kdevprj | Developer | KDevelop Project File |
| .kdk | Raster Image | Kodak Proprietary Decimated TIFF File |
| .kext | System | Mac OS X Kernel Extension |
| .key | System | Security Key (Most common) |
| .kfx | Image | Kofax Image File |
| .kgb | Compressed | KGB Archive File |
| .khd | Misc | Dynamics AX Kernel Help Data File |
| .khi | Misc | Dynamics AX Kernel Help Index File |
| .kic | Raster Image | Kodak Compressed Image File |
| .kid | Data | Kidspiration Document |
| .kin | Audio | Kinetic Music Project |
| .kix | Executable | KiXtart Script File |
| .klg | Text | Log File (Most common) |
| .kmc | Image | Kinemac Animation File |
| .kmcobj | Image | Kinemac Sprite Object |
| .kml | Text | Keyhole Markup Language |
| .kmm | Plugin | K-Meleon Macro Module |
| .kmp | Audio | Korg Trinity/Triton Keymap File |
| .kmz | Data | Google Earth Placemark File |
| .knt | Text | KeyNote Note File |
| .kodak | Image | Kodak Photo CD File |
| .kon | Text | Yahoo! Widget XML File |
| .koz | Audio | Audiokoz Music File (Most common) |
| .kpf | Data | Komodo Project File |
| .kpg | Raster Image | Kai's Power Goo Graphic |
| .kpp | Data | Kid Pix Presentation |
| .kpr | Data | KPresenter Presentation |
| .kpx | Data | Kid Pix Picture |
| .kpz | Data | Komodo Template File |
| .krz | Audio | Kurzweil K2000 File |
| .ksc | Audio | Korg Trinity/Triton Script File |
| .ksf | Audio | Korg Trinity/Triton Sample File |
| .ksh | Executable | Unix Korn Shell Script |
| .kth | Misc | Keynote Theme |
| .ktp | Audio | Kinetic Project Template |
| .kwd | Text | KWord Document |
| .kwreplay | Game | Command & Conquer 3 Replay File |
| .kyb | Settings | Keyboard Layout |
| .kyr | Misc | Lotus Domino Key Ring File |
| .kys | Settings | Adobe Photoshop CS Keyboard Shortcut File |
