https://tools.ietf.org/html/rfc7231#section-4.3.1 https://tools.ietf.org/html/rfc7231#section-4.3.1 says: > A payload within a GET request message has no defin

https://tools.ietf.org/html/rfc7231#section-4.3.1 https://tools.ietf.org/html/rfc7231#section-4.3.1 says: > A payload within a GET request message has no defined semantics; sending a payload body on a GET request might cause some existing implementations to reject the request. So it's non-non-standard but not standard either. If I understand correctly a GET with body is about as defined as a POST with body, but since it is not often used the real world support is worse. What is a lot better specified about POST is response codes, like 201 Created and (I'm guessing) content negotiation. Browsers seem pretty strict about it though, `fetch('/', {body: ''})` gives a TypeError for me but `fetch('/', {body: '', method: 'POST'})` does not.