I am not 100% sure, but I think I read somewhere (at least 2 years ago), that browsers are actually faster using JSON than Protobuf (a bit counter-intuitive).

I am not 100% sure, but I think I read somewhere (at least 2 years ago), that browsers are actually faster using JSON than Protobuf (a bit counter-intuitive). Nevertheless, bandwidth-wise it could make sense anyway, but I think it makes sense to consult some benchmarks in this case.