| .jpg2 |
JPEG 2000 Image |
| .jnilib |
JNI Library |
| .jsd |
Jazer Data File |
| .jcrypt |
JCRYPT File |
| .jmv |
Jnes Movie File |
| .j6i |
Ricoh Camera Image File |
| .jcr |
Nonogram Puzzle File |
| .jar.pack |
Pack200 Packed Jar File |
| .jrz |
PSP Game Data File |
| .jbmp |
JAmes OS Bitmap Image |
| .jo-7z |
jo Audio File |
| .jo |
jo Audio File |
| .jrc |
PCjr Cartridge ROM File |
| .jsda |
Jazer Data File |
| .jac |
JaStaCry Encrypted File |
| .jbg |
Joint Bi-level Image Group File |
| .keychain |
Mac OS X Keychain File |
| .kdc |
Kaspersky Virus Database File |
| .kfx |
Amazon KF10 eBook File |
| .kext |
Mac OS X Kernel Extension |
| .kth |
Keynote Theme |
| .ko |
Linux Kernel Module File |
| .kpl |
Kids Programming Language File |
| .kb2 |
Kleo Backup File |