Looked at both. ffjson is a library that generates the marshaling&#x2F;unmarshaling Go code for your structs, so it doesn&#x27;t support my use case at all. megajson is abandonware (&quot;This tool is unmaintained. Please use ffjson instead&quot;).<p>go-codec [1] is very good, and can do things like interning string keys to reduce allocation overhead, but it&#x27;s not faster than encoding&#x2F;json when working on plain maps.<p>[1] <a href="https:&#x2F;&#x2F;github.com&#x2F;ugorji&#x2F;go" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;ugorji&#x2F;go</a>