PNM is a generic term for PBM, PGM, and PPM formats from the Netpbm family.
G3 (Group 3) is a fax image format using ITU-T T.4 compression, the standard for document facsimile transmission.
FreeFileConvert uses tuned encoding for PNM to G3 conversions, preserving clarity while trimming file size. Finished audio streams instantly across phones, tablets, desktops, and modern browsers without extra tweaks.
Upload PNM files from desktop, tablet, or cloud storage, queue multiple jobs, and let the converter finish autonomously. Return whenever convenient to download synchronized G3 results on any device you rely on.
Process up to 5 files sized 1000 MB per batch without splitting queues manually. Mixed-format uploads convert together, producing consistent G3 audio with dependable progress tracking.
PNM files use simple ASCII or binary format for portable image storage.
G3 uses Modified Huffman (MH) run-length encoding optimized for black-and-white documents.
Upload your image file in the PNM format from your device, Dropbox, or Google Drive.
Select G3 as the output format and click Convert. Adjust optional settings if needed.
Download the converted image file. Each file stays available for up to 5 downloads.