HTTP 203 Non-Authoritative Information vs 304 Not Modified
HTTP 203 (Non-Authoritative Information) is a 2xx Success response, while 304 (Not Modified) is a 3xx Redirection response. 203 indicates that the response payload has been modified by a transforming proxy from the origin server's 200 response. In contrast, 304 means that the resource has not been modified since the last request. The client can use its cached copy.
Descripción
The response payload has been modified by a transforming proxy from the origin server's 200 response.
Cuándo lo verás
When a proxy or CDN modifies the response body (e.g., adds headers, transforms content).
Cómo solucionarlo
Check if a proxy is modifying the response. Access the origin directly if you need the original content.
Descripción
The resource has not been modified since the last request. The client can use its cached copy.
Cuándo lo verás
When the browser cache is still valid (If-None-Match / If-Modified-Since headers match).
Cómo solucionarlo
No fix needed. This saves bandwidth by confirming the cached version is still current.
Diferencias clave
203 is a 2xx Success response, while 304 is a 3xx Redirection response.
HTTP 203: The response payload has been modified by a transforming proxy from the origin server's 200 response.
HTTP 304: The resource has not been modified since the last request. The client can use its cached copy.
You encounter 203 when when a proxy or CDN modifies the response body (e.g., adds headers, transforms content).
You encounter 304 when when the browser cache is still valid (If-None-Match / If-Modified-Since headers match).
Cuándo usar cada uno
For 203 (Non-Authoritative Information): Check if a proxy is modifying the response. Access the origin directly if you need the original content. For 304 (Not Modified): No fix needed. This saves bandwidth by confirming the cached version is still current.