| inr | SAP BR Tools Incremental Backup Archive |
| ipd | BlackBerry Phone Backup |
| ipg | iPod Game Package |
| ipk | Zaurus Install Package |
| ipsw | iPhone / iPod Software Update |
| iqb | AmeriCalc Backup |
| irz | iROS Application Package |
| isdocx | ISDOC Archive |
| ispac | Microsoft SQL Server Deployment Packet |
| ita | IconTweaker Theme Archive |
| itmsp | iTunes Store Package |
| iwa | iWork Archive File |
| iwzip | Incomedia Website X5 Project Archive |
| ixn | Mentor Graphics Service Pack Archive |
| ize | IZArc Encrypted Archive |
| j01 | Akeeba Secured Backup Archive |
| j01 | Akeeba Multi-part Backup Archive |
| j02 | Akeeba Secured Backup Archive |
| j02 | Akeeba Multi-part Backup Archive |
| j03 | Akeeba Secured Backup Archive |
| j03 | Akeeba Multi-part Backup Archive |
| j04 | Akeeba Secured Backup Archive |
| j04 | Akeeba Multi-part Backup Archive |
| j05 | Akeeba Secured Backup Archive |
| j05 | Akeeba Multi-part Backup Archive |
| jar | Java Archive |
| jbackup | The Journal Backup Archive |
| jdb | Symantec Endpoint Protection Update |
| jgz | JNode Module Package |
| jisp | Tkabber Emoticon Set |
| jma | NSRT Compressed Game ROM |
| jpa | Akeeba Multi-part Backup Archive |
| jpa | JoomlaPack Backup Archive |
| jps | Akeeba Secured Backup Archive |
| jp_ | Compressed Microsoft JPEG Image |