| Extension | File Type | Files scanned | Contributor |
| N | Neko bytecode | 3 | |
| NAB | Novell Groupwise Address Book | 7 | |
| NARC | Nintendo ARChive | 2 | |
| NB | Mathematica Notebook | 13 | |
| NBF | NVIDIA Scene Graph binary | 17 | |
| NBI | Ahead Nero BackItUp file (v1.x) | 10 | |
| NC | NetCDF Network Common Data Form | 17 | |
| NCC | Nokia PC Suite Content Copier file | 4 | |
| NCD | Nero CoverDesigner | 18 | Joystick |
| NCS | KOTOR (Knight Of The Old Republic) compiled script | 6 | |
| NCT | Ahead Nero CoverDesigner Template | 16 | |
| NDB | SeeYou Waypoint | 5 | |
| NDF | Channel Data File | 12 | |
| NDM | Enemy Territory: Quake Wars demo | 9 | |
| NDS | Nintendo DS ROM image | 13 | |
| NDX | WinDev Index | 36 | |
| NEC | NEC JIS encoded file | 3 | |
| NEF | Nikon raw image | 6 | |
| NEO | Atari NeoChrome bitmap | 4 | |
| NES | Nintendo Entertainment System ROM | 11 | |
| NET | Epanet data file | 6 | |
| NET | SNNS network definition | 12 | |
| NEU | Gambit Neutral file | 6 | |
| NFC | Nokia PC Suite Content Copier file | 13 | |
| NFF | WorldToolKit Neutral File Format | 6 | |
| NFG | Gambit Normal Form representation | 49 | |
| NGG | Nokia Group Graphics bitmap | 21 | |
| NIB | Apple Interface Builder resource | 8 | |
| NIF | GameBryo file format | 3 | |
| NIF | NetImmerse file format | 6 | |
| NIF | Notation Interchange File Format | 18 | |
| NII | NIfTI-1 data format | 33 | |
| NK2 | Outlook AutoComplete file | 4 | |
| NLM | Netware Loadable Module | 8 | |
| NLM | Nokia Logo Manager bitmap | 22 | |
| NM2 | Navitel 3.1 Map | 3 | |
| NMEA/NMA | NMEA GPS log data | 6 | |
| NMF | Normal Map | 4 | |
| NMV | Nintendulator movie capture | 4 | |
| NOA | Nancy Codec video | 4 | |
| NOL | Nokia Operator Logo bitmap | 21 | |
| NOTEBOOK | SMART Notebook | 9 | |
| NPK | MikroTik RouterOS Upgrade Package | 14 | |
| NPL | Xilinx Integrated Software Environment Project file | 14 | |
| NPM | Corel Custom Natural Media Stroke | 23 | |
| NPP | Art Explosion Publisher Pro document | 7 | |
| NQI | NOD32 Quarantined file Information | 4 | |
| NR3 | Nero MP3 ISO Compilation | 14 | |
| NRA | Nero Audio-CD Compilation | 4 | |
| NRG | Nero BurningROM CDImage | 4 | THE LoW |
| NRG | Nero BurningROM CDImage (RAW Format) | 3 | THE LoW |
| NRI | Nero ISO Compilation | 11 | |
| NRI | Tricksteronline image | 2 | |
| NRV | Nero Video-CD compilation | 6 | |
| NS1 | NetStumbler NS1 log | 5 | |
| NSF | NES sound/music/code dump | 14 | |
| NSK | NaShrinK compressed archive | 3 | |
| NSP | Computerized Speech Lab NSP audio | 6 | |
| NSV | Nullsoft Streaming Video | 8 | |
| NSX | Index Apollo Database Engine | 5 | Knuth Konrad |
| NTF | NITF National Imagery Transmission Format image | 6 | |
| NTF | National Transfer Format Map | 7 | |
| NTH | Nokia theme | 6 | |
| NTM | Navitel 2.0 Map | 35 | |
| NTP | NovoTrade Packer Music | 14 | |
| NTT | Neato MediaFACE label template | 14 | |
| NTW | Lode Data Network | 4 | |
| NUP | NOD32 Antivirus Update file | 143 | Ildar Ibatullin |
| NUT | NUT Open Container Format | 3 | |
| NUV | NuppelVideo (MythTV) video | 3 | Ariel |
| NV | Juno address book | 9 | |
| NVB | NVIDIA Scene | 16 | |
| NVC | NeroVision Express project | 3 | |
| NVF | Creative Nomad II series MP3 players Voice File audio | 12 | |
| NW | GraalOnline level | 2 | |
| NWC | NoteWorthy Composer song | 12 | |
| NWC | NoteWorthy song (alternate format) | 18 | |
| NWC | Noteworthy Composer data file | 8 | Joachim Grabinski |
| NWP | Neo Content file | 11 | |
| NXV | NXV video | 4 | |
| NY | Audacity Nyquits plug-in | 21 | |
| NYF | myBase database | 5 | |
| NZB | Newzbin Usenet Index | 7 | |
