Convert image to Base64

This is a companion discussion topic for the original entry at


I have tried the flow, it is working fine in local client Knime but when run in Knime server, it showed the error like the attached image, both method in this workflow gave the same error.

I also found out that the converted base64 string are different between local client and Knime Server.


Hi @tansk,

its a bit odd that the svg cannot be rendered on the Server - however, this should not have to do with the base64 image decoding but with a different error. However, image generation does work with your workflow on the server, right? I updated the workflow so that it uses another image, so that this part should work for now.

If you send the base64-images via email, does this work correctly on either server or locally with either of the wo methods? It seems to me that there is some difference in encoding (UTF-8 vs ASCII for example) - but maybe your email program is smart enough to know the difference and act correctly.

If not, could you post the strings please so that we can investigate?

Kind regards,

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As you look into the base64 encoding mismatch, I thought I’d share a handy tool that could help - there’s an online Image to Base64 Converter at Image Base64 that lets you validate and compare base64 strings. It’s great for spotting encoding problems. Feel free to check it out if useful as you’re investigating the SVG issues further.

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