> MessagePack and CBOR are equivalent. MessagePack has an ugly history with text data that's still reflected in some of the libraries interfaces. E.g., the Pyt

> MessagePack and CBOR are equivalent. MessagePack has an ugly history with text data that's still reflected in some of the libraries interfaces. E.g., the Python library doesn't round-trip strings by default. (They'll turn into bytes objects.) There's a flag to do the right thing, but not everyone is aware of it. Add to that that CBOR has an RFC, and I'll pick it over MessagePack every time. Binary formats are mostly nicer from a parsing perspective: it's much easier to unpack. You're right, I think, that simple compression will mostly close any size gap.