LanguagePNJ
Portable Network JPEG format
File type: Bitmap image file
Files with pnj extension are pictures in variant of Portable Network JPEG format. JPEG compression with transparent layer.
What is pnj file?
File type category:
Bitmap image file
Date updated: June 23, 2025
File extension pnj is probably best known for it's original use for Portable Network JPEG format, until the default extension was changed to more appropriate jng file extension. But otherwise it's just like JNG format, i.e. JPEG compression with transparent layers preserved.
How to open pnj file?
Any tool that can read JNG format can read PNJ as well, just rename the extension if you need to.
How to convert pnj file?
Export to other graphics formats is possible.
Associated software actions with the pnj file
Programs for viewing pnj files:
XnView MP (Multiplatform)