103 Early Hints
The 103 Early Hints status code allows a server to tell browsers what to pre-fetch (with link headers) before the final response is available (e.g. because the server needs to "think", or because it's fetching something from another server).
This is functionally similar to HTTP/2 server push, but simpler and more interoperable.
- Specification: https://tools.ietf.org/html/rfc8297
- Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1407355
- Chrome: https://bugs.chromium.org/p/chromium/issues/detail?id=671310