1xx Informational

HTTP 103 Early Hints

The server sends preliminary headers to the client before the final response. This allows the browser to start preloading resources like stylesheets and scripts while the server prepares the full response.

Common Causes

  • Server sending Link headers for resource preloading
  • CDN or reverse proxy providing early hints
  • Performance optimization for critical resources

How to Fix

  1. 1No fix needed — this improves page load performance
  2. 2Ensure the Link headers point to valid resources
  3. 3Verify browser supports 103 Early Hints

Example

HTTP 103 Early Hints
103 Early Hints
Link: </style.css>; rel=preload; as=style

→ Browser begins fetching style.css
→ Server sends final 200 OK response

Related Informational Codes

100

Continue

101

Switching Protocols

102

Processing