Hey there,
I could only download Facebook messenger conversation in JSON format. I cannot read it and it's mess at best when opened in Chrome browser. Please can anyone help me and tell me how to convert it to readable format with all graphics that accompany messenger?

I don't know of any scripts or apps that work with FB messenger exports, everyone seems to just write what they need in regards to formatting the data.

You can use any of the online json decoders but the result won't look a whole lot better, it will be just a slightly less confusing looking array. Prettifying would require additional steps after the decode. Also, if the images are part of the json, they'll most likely be encoded differently using something like base64 so that would require an additional step.

Are you handy in any scripting or programming languages?