← All Status Codes
103
Early Hints
ℹ️ Informational
Info Risk
📖 What Is HTTP 103?
Allows the server to send preliminary response headers before the final response. Used to preload resources like CSS and JavaScript while the server processes the request.
🛡️ Security Implications
Low risk. Ensure preloaded resources are served over HTTPS to prevent mixed content issues.
🔍 Common Causes
Server uses Link headers to hint the browser to preload critical resources before the full response is ready.
🔧 How to Fix
Implement 103 Early Hints to improve page load performance. Use with Link: </style.css>; rel=preload headers.
🖥️ How to Check
curl -I -o /dev/null -w "%{http_code}" https://example.com