103 Early Hints

What it means

The server sends Link headers (for example preload or preconnect) while it is still generating the page, which can improve load times.

Common causes

• The server or CDN is configured to send Early Hints.

How to fix it

1. No action is needed; it is a performance feature.
2. Only hint critical resources that every visit needs.

Example response

HTTP/1.1 103 Early Hints
Link: </styles.css>; rel=preload; as=style

Worked example

A client sends Expect: 100-continue before uploading a large request body. The server's interim response tells it to continue; the client still waits for the final response after sending the body.

How to read this response

1. Find the status line in your browser's Network panel, API client, or server access log.
2. Read the response body and headers shown above; headers such as Location, Allow, Retry-After, and WWW-Authenticate explain the next step.
3. Use the code's class to orient your diagnosis: informational, successful, redirected, request-related, or server-side.

How to check a status code

Enter a URL in the HTTP Status Checker to see its status code, every redirect hop, and response time. For redirect-heavy pages, the Website Speed Test shows how much time redirects add.

Frequently asked questions

What it means: HTTP 103

103 Early Hints: An interim response that lets the browser start preloading resources before the final response is ready.

Common causes: 103

The server or CDN is configured to send Early Hints.

How to fix it: HTTP 103

No action is needed; it is a performance feature. Only hint critical resources that every visit needs.

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