PNG to base64 string?


Hi there, 

Is there a way to convert a PNG image in a KNIME table to base64 string?


Many thanks,





Hi George,

depending on your use-case also the "PNGs to Binary Objects" and "Binary Objects to PNGs" nodes might help. They are part of the "File Handling" Nodes which you can install via the KNIME Update-site.

Does this help? If not I will try to figure out how you can converts your PNGs to Base64 Strings (maybe JavaSnippet Node can help you).





1 Like


Hi @christian.dietz,

I tried several options like:

  • Converto to binary object > Java node convert binary array to base64
  • Convert to binary object > Convert to string > Java node convert base64
  • Save locally > read and convert via a Java node only

Unfortunately, I failed all the time. I’d really appreciate your advice as Java is totally new for me.

Thanks a lot



Have you tried to use an external tool like R? There was a discussion with an Excel file:

1 Like