Toronto SEO
All HTTP status codes
1xx Informational
RFC 8297

103 Early Hints

Used to return preliminary HTTP headers (such as Link) before the final response is ready.

What it means

HTTP 103 Early Hints lets the server send Link headers (such as preload or preconnect hints) to the user agent before the final response, allowing the browser to start fetching critical resources sooner and improving perceived performance.

When it's used

Performance optimization — the server hints at critical CSS, JS, or fonts the browser should preload while the main response is being generated.

Common causes
  • Server-pushed resource hints for Largest Contentful Paint optimization
  • Cloudflare or Fastly Early Hints feature enabled
  • HTTP/2 or HTTP/3 with backend support
How to fix it
  • Not an error — performance feature
  • Verify your CDN or origin sends correct preload hints
  • Test with Chrome 103+ which supports rendering on Early Hints
Example response
HTTP/1.1 103 Early Hints
Link: </style.css>; rel=preload; as=style
Link: </main.js>; rel=preload; as=script
SEO impact

Indirect positive impact — improves LCP and Core Web Vitals, which are confirmed Google ranking factors.