While most people would prefer the second version, the first version is also valid JSON and will definitely see use when you want/need JSON but want to reduce d

While most people would prefer the second version, the first version is also valid JSON and will definitely see use when you want/need JSON but want to reduce data over the wire though you'd probably still see a wrapper object like: { headers: ["field1","field2","fieldN"], values: [["value (0,0)","value (0,1)","value (0,n)"], ["value (1,0)","value (1,1)","value (1,n)"], ["value (2,0)","value (2,1)","value (2,n)"]] }