The standard library's JSON encoder is slow. And JSON is not efficient. BSON is where JSON should have been, at least eliminating base64 encoding to transfer bytes.
The non-standard library JSON encoders either require code generation (which you might as well use proto as it encodes better) or can't support the full feature set.
I was being lazy recently and I decided to use JSON for encoding an internal frame over a Unix socket. When I compared to gRPC I was being destroyed in packets per second. Switching to a proto fixed this.
I thought it might be base64 encoding of the byte content. That added a small bit of overhead. Frankly the built in encoder is just slow.
I think the benchmarks speak for themselves. I didn't even bother benmarking the decodes, the encoding was enough to convince me.
- *WithStr means the data is just a string
- -*WithBytes means the data is a byte, which in JSON gets base64 encoded
BenchmarkJSONEncodingWithStr/_10kiBStr-16 119774 9748 ns/op 10914 B/op 2 allocs/op BenchmarkJSONEncodingWithStr/_100kiBStr-16 13214 91671 ns/op 107140 B/op 2 allocs/op BenchmarkJSONEncodingWithStr/_1miBStr-16 1292 875316 ns/op 1080500 B/op 2 allocs/op BenchmarkJSONEncodingWithBytes/_10kiBBytes-16 100412 11924 ns/op 15562 B/op 3 allocs/op BenchmarkJSONEncodingWithBytes/_100kiBBytes-16 10000 110331 ns/op 143101 B/op 3 allocs/op BenchmarkJSONEncodingWithBytes/_1miBBytes-16 1125 1053090 ns/op 1674998 B/op 4 allocs/op BenchmarkProtoEncodingWithBytes/_10kiBBytes-16 718411 1440 ns/op 10880 B/op 1 allocs/op BenchmarkProtoEncodingWithBytes/_100kiBBytes-16 95144 12543 ns/op 106496 B/op 1 allocs/op BenchmarkProtoEncodingWithBytes/_1miBBytes-16 8842 126329 ns/op 1032192 B/op 1 allocs/op