| kry | Krypter Encrypted Data |
| ksp | KeyShot Package |
| kva | KVIrc Compressed Archive |
| kwt | KVIrc Theme Pack |
| kz | KuaiZip Compressed File |
| lal | Liberkey Core Update File |
| lbr | LU Library Archive |
| lcb | Living Cookbook Backup |
| lemon | LemonShare.net Download |
| lg | Arhangel Compressed Archive |
| lgu | LG Windows CE Device Firmware Update |
| lha | LH ARC Archive |
| lhw | LhWarp Compressed Archive |
| liz | Liberty Instruments LAUD Program Update |
| lja | ljArchive Archive |
| lks | Liberkey Installation Package |
| lnx | Commodore 64 Lynx Archive |
| lok | WinGuard Pro Lok Archive |
| lou | Liquidware LouZip Archive |
| lpk | Lazarus Package |
| lpkg | Liferay Package |
| lqr | Squeezed LBR Archive |
| lrp | Linux Router Project Package |
| lrz | Long Range Zip Compressed Archive |
| lz | Lzip Compressed File |
| lz4 | LZ4 Compressed Data |
| lzg | LZG Compressed Data |
| lzh | LH ARC Archive |
| lzip | Lzip Compressed File |
| lzm | Slax Module |
