| Extension | File Type | Files scanned | Contributor |
| L2R | Lineage II Replay | 4 | |
| L2R | Lineage II data | 2 | |
| L4D | CINEMA 4D Layout | 2 | |
| L64 | 64LAN image | 12 | |
| LA | La Lossless Audio compressed (generic) | 66 | |
| LA | La Lossless Audio compressed (v0.2) | 13 | |
| LA | La Lossless Audio compressed (v0.3) | 53 | |
| LA | La Lossless Audio compressed (v0.4) | 53 | |
| LAB | Bar-One Lite label | 12 | |
| LAN/GIS | Erdas bitmap | 15 | |
| LAS | Log ASCII Standard | 20 | |
| LB | Low Bitrate Packer compressed audio | 5 | |
| LBR | EAGLE Library | 86 | |
| LBR | LU library | 2 | |
| LBS | Omnis Studio Library | 78 | |
| LDF | LuraDocument Format bitmap | 21 | |
| LDF | Microsoft SQL Server 2000 log | 14 | Andreas |
| LDIF | LDAP Data Interchange Format | 10 | |
| LDR | GoDot C64 Image Processing - Loader | 24 | |
| LDR | LDraw Model | 15 | |
| LDX | Liquid Executable bytecode | 142 | |
| LEF | LEN Exchange Format | 8 | |
| LEF | Lenex XML data | 8 | |
| LFD | LucasFilm Data - LucasArts game resource | 14 | |
| LGO | Modern ListGeo Output | 94 | |
| LGP | Final Fantasy Game Archive | 2 | |
| LGX | Logistix spreadsheet | 4 | |
| LHTS | The Movies Editor Text String Database | 3 | |
| LIB | Microsoft Basic 7.x compiled library | 46 | |
| LIB | OrCAD Library model | 8 | |
| LIC | ESET NOD32 Antivirus License data | 7 | |
| LID | Lextek Language Identification Module | 4 | |
| LIM | Limit compressed archive | 11 | |
| LIQ | Liquid Tracker song/module | 5 | |
| LIT | Microsoft Reader eBook | 514 | |
| LIT | Quake colored light data | 11 | |
| LKD | Pioneer OEL screensaver | 13 | |
| LL | Combit List and Label printer setup file | 15 | |
| LLSD | Linden Lab Structured Data | 6 | |
| LMA | Learning Mobile Author (LMA) Project | 5 | |
| LME | LegglessMusicEditor song/module | 5 | |
| LMU | RPG Maker 2000/2003 Map | 6 | |
| LNG | SourceEdit Language Definition | 29 | |
| LNK | Windows Shortcut | 506 | |
| LNX | Atari Lynx ROM | 23 | |
| LOC | Topografix's EasyGPS/TerraByte Location file | 13 | |
| LOG | HijackThis logfile | 3 | |
| LOG | Wise Installer log | 14 | |
| LOGONXP | LogonStudio theme | 9 | |
| LP | LaTeX-CAD drawing | 16 | |
| LPD | Lecturnity Player file | 22 | Meigel |
| LQT | Liquid Audio | 4 | |
| LRC | Lyric file (with ID tags) | 8 | |
| LRF | Unencrypted BBeB - BroadBand eBook | 8 | |
| LRS | Lexar Encrypted file | 3 | |
| LSC | LOGO!Soft Comfort Circuit | 11 | |
| LSD | ABBYY Lingvo dictionary | 55 | kif aka AC |
| LST | Kaspersky Lab black list file | 3 | |
| LSZ | Litestep theme | 8 | |
| LTF | Frogans Short-cut | 8 | |
| LVA | Logitech Video Effects Avatar | 6 | |
| LVF | Logitech Video Effects Face Accessory | 10 | |
| LVM | LabVIEW Measurement | 8 | |
| LVM | LiveSwif Movie (ungzipped) | 6 | |
| LW | LiteWave compressed audio | 48 | |
| LWF | LuraWave Format bitmap | 21 | |
| LWO | Lightwave Object | 59 | |
| LWP | Lotus Word Pro document | 6 | |
| LWS | LightWave 3D Scene | 21 | |
| LWTP | LimeWire theme | 12 | |
| LXF | LEGO project / scene | 5 | |
| LXF | SPLASH - Lenex compressed data | 7 | |
| LXFML | LEGO Digital Designer XML data | 13 | |
| LYR | Project Dogwaffle layered bitmap | 7 | |
| LYT | PCB Layout | 7 | |
| LZA | LZA animation/video | 3 | |
| LZH/LHA | LHARC/LZARK compressed archive | 28 | |
| LZMA | Lzma compressed archive | 64 | selepo |
| LZO | lzop compressed | 5 | |
| LZX | LZX Amiga compressed archive | 83 | Lukasz Jakubowski |
