Filtillägg börjar med tecknet "J"
| FILTYP | Kategori | Filformat | |
|---|---|---|---|
| .j | Development Files | Java Källfil | |
| .jad | Multiple Use Files | Java Application beskrivningsfilen | |
| .jam | CAD Files | Jam STAPL fil | |
| .jar | Program Execution Files | Java Arkivfil | |
| .jasper | Data Files | Jasper datafil | |
| .jav | Development Files | Java Källfil | |
| .java | Development Files | Java källkod fil | |
| .jbi | Data Files | Motoman Robot jobbfil | |
| .jdb | Data Files | Symantec Endpoint Protection Update File | |
| .jdc | Backup Files | JDownloader Links Fil | |
| .jef | Data Files | Janome broderi Format | |
| .jfif | Raster Graphics Files | JPEG-fil Interchange Format | |
| .jgz | Compressed Files | Gzippad JavaScript-fil | |
| .jic | Compressed Files | Java Ikonfil | |
| .jis | Text Files | Japansk industristandard Text | |
| .jmp | Data Files | JMP datafil | |
| .jnilib | Development Files | JNI Bibliotek | |
| .jnlp | Java Files | Java Web Start-fil | |
| .jnt | Microsoft Files | Windows Journal-fil | |
| .jo | Audio Files | jo ljudfil | |
| .joined | Data Files | HJ-Split datafil | |
| .jp1 | Text Files | Japanska (Romaji) textfil | |
| .jp2 | Raster Graphics Files | JPEG 2000 Core Image File | |
| .jpc | Raster Graphics Files | JPEG 2000 Kod Stream Arkiv | |
| .jpd | Development Files | Java Process Definition | |
| .jpeg | Raster Graphics Files | JPEG-bild | |
| .jpg | Raster Graphics Files | JPEG-bild | |
| .jpg2 | Raster Graphics Files | JPEG 2000 Bild | |
| .jpgw | Graphics Files | JPEG World Arkiv | |
| .jps | Raster Graphics Files | Stereo JPEG-bild | |
| .jrprint | Data Files | Jasper Skriv ut fil | |
| .jrtf | Text Files | James OS Rich textfil | |
| .jrxml | Data Files | Jasper Layout File | |
| .js | JavaScript Files | JavaScript Arkiv | |
| .jse | Program Execution Files | JScript kodade filen | |
| .json | JavaScript Files | JavaScript Object Notation fil | |
| .jsp | Java Files | Java Server Page | |
| .jsx | Program Execution Files | ExtendScript Script fil | |
| .jude | Data Files | JUDE Project File | |
| .jws | Java Files | Java Web Services File |