103 Early Hints
An informational response sent before the final one, carrying Link headers so the browser can start preloading or preconnecting while the server prepares the page.
1xx · Informational
Typical causes
A server or CDN that knows a page's critical CSS, fonts or scripts in advance and sends Link: <…>; rel=preload hints early to cut load time.
Defined in RFC 8297, §2