HTTP 103 Early Hints vs 401 Unauthorized
HTTP 103 (Early Hints) is a 1xx Informational response, while 401 (Unauthorized) is a 4xx Client Error response. 103 indicates that used to return some response headers before the final HTTP message. Allows the browser to start preloading resources while the server prepares the response. In contrast, 401 means that the request requires user authentication. The response includes a WWW-Authenticate header indicating the authentication scheme.
Description
Used to return some response headers before the final HTTP message. Allows the browser to start preloading resources while the server prepares the response.
When You See It
When a server wants the browser to start loading CSS/JS before the full response is ready.
How to Fix
No fix needed. This optimization helps speed up page loading.
Description
The request requires user authentication. The response includes a WWW-Authenticate header indicating the authentication scheme.
When You See It
When accessing a protected resource without credentials or with expired tokens.
How to Fix
Include valid authentication credentials (API key, Bearer token, Basic auth) in the Authorization header.
Key Differences
103 is a 1xx Informational response, while 401 is a 4xx Client Error response.
HTTP 103: Used to return some response headers before the final HTTP message. Allows the browser to start preloading resources while the server prepares the response.
HTTP 401: The request requires user authentication. The response includes a WWW-Authenticate header indicating the authentication scheme.
You encounter 103 when when a server wants the browser to start loading CSS/JS before the full response is ready.
You encounter 401 when when accessing a protected resource without credentials or with expired tokens.
When to Use Which
For 103 (Early Hints): No fix needed. This optimization helps speed up page loading. For 401 (Unauthorized): Include valid authentication credentials (API key, Bearer token, Basic auth) in the Authorization header.