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.
Descrição
The response payload has been modified by a transforming proxy from the origin server's 200 response.
Quando você o vê
When a proxy or CDN modifies the response body (e.g., adds headers, transforms content).
Como corrigir
Check if a proxy is modifying the response. Access the origin directly if you need the original content.
Descrição
The resource has not been modified since the last request. The client can use its cached copy.
Quando você o vê
When the browser cache is still valid (If-None-Match / If-Modified-Since headers match).
Como corrigir
No fix needed. This saves bandwidth by confirming the cached version is still current.
Diferenças principais
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).
Quando usar qual
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.