cdm

Compact Discord Messages file format (.cdm)

a .cdm file stores discord message data like content, user id, attachments and such
note that this is NOT in human readable format, so you can't open it in a traditional text editor and read it

if you wanted to store/export discord messages and process them later using code or other tools, your only other option would have been storing them in JSON

not only is JSON an objectively bad language but it is also inefficient in space and parsing

imagine for example trying to encode image data using JSON, it would be a mess!

so cdm solves this highly specific problem

data in a .cdm file is highly compact and optimized, here is how it's done:

• not human readable but easily parsable
• using integers instead of bytes
• smart attachments
• keep the data you need
• no repetition

you can use cdm in 2 ways:

• to encode data into a .cdm file, which can be done manually or by converting from a .json file (exported from DiscordChatExporter)
• to decode data from a .cdm file and use it for your needs

to see what's in a .cdm file you would need to read one using a hex editor

now in order to understand what's going on you would of course need to understand the cdm file format specification

but since that's complex, you could understand it better using ImHex and its pattern editor

open a .cdm file using ImHex and open the pattern editor and paste everything from cdm/cdm.pat

press F5 to refresh and you should see your beautiful color-coded data like this: