More like browsers can de-serialize JSON5 natively. writing a JSON5 parser is not difficult. It's just not part of most std libs in most languages, but I would argue that most std libs don't parse YAML either.

JSON5 is a good compromise.

Neither Chrome nor Firefox's JSON.parse accept JSON5. I'm not sure what browser API you mean.

For example,

  JSON.parse(`{"foo":"bar",}`)

throws a syntax error.

> Neither Chrome nor Firefox's JSON.parse accept JSON5. I'm not sure what browser API you mean.

This is a typo, I meant "can't" not "can". Off course browsers don't support JSON5 or my message makes no sense whatsoever.