HTTP 203 Non-Authoritative Information vs 412 Precondition Failed
HTTP 203 (Non-Authoritative Information) is a 2xx Success response, while 412 (Precondition Failed) is a 4xx Client Error response. 203 indicates that the response payload has been modified by a transforming proxy from the origin server's 200 response. In contrast, 412 means that one or more conditions in the request headers (If-Match, If-Unmodified-Since) evaluated to false.
Description
The response payload has been modified by a transforming proxy from the origin server's 200 response.
Quand vous le voyez
When a proxy or CDN modifies the response body (e.g., adds headers, transforms content).
Comment résoudre
Check if a proxy is modifying the response. Access the origin directly if you need the original content.
Description
One or more conditions in the request headers (If-Match, If-Unmodified-Since) evaluated to false.
Quand vous le voyez
When using conditional requests with ETags and the resource has changed.
Comment résoudre
Refresh the ETag/Last-Modified value and retry with updated preconditions.
Différences clés
203 is a 2xx Success response, while 412 is a 4xx Client Error response.
HTTP 203: The response payload has been modified by a transforming proxy from the origin server's 200 response.
HTTP 412: One or more conditions in the request headers (If-Match, If-Unmodified-Since) evaluated to false.
You encounter 203 when when a proxy or CDN modifies the response body (e.g., adds headers, transforms content).
You encounter 412 when when using conditional requests with ETags and the resource has changed.
Quand utiliser lequel
For 203 (Non-Authoritative Information): Check if a proxy is modifying the response. Access the origin directly if you need the original content. For 412 (Precondition Failed): Refresh the ETag/Last-Modified value and retry with updated preconditions.