HTTP

HTTP 200 OK vs 412 Precondition Failed

HTTP 200 (OK) is a 2xx Success response, while 412 (Precondition Failed) is a 4xx Client Error response. 200 indicates that the request succeeded. The meaning depends on the HTTP method: GET returns the resource, POST reports the action result, HEAD returns headers only. In contrast, 412 means that one or more conditions in the request headers (If-Match, If-Unmodified-Since) evaluated to false.

Descripción

The request succeeded. The meaning depends on the HTTP method: GET returns the resource, POST reports the action result, HEAD returns headers only.

Cuándo lo verás

The most common HTTP response — indicates the request was processed successfully.

Cómo solucionarlo

No fix needed. The request succeeded as expected.

Descripción

One or more conditions in the request headers (If-Match, If-Unmodified-Since) evaluated to false.

Cuándo lo verás

When using conditional requests with ETags and the resource has changed.

Cómo solucionarlo

Refresh the ETag/Last-Modified value and retry with updated preconditions.

Diferencias clave

1.

200 is a 2xx Success response, while 412 is a 4xx Client Error response.

2.

HTTP 200: The request succeeded. The meaning depends on the HTTP method: GET returns the resource, POST reports the action result, HEAD returns headers only.

3.

HTTP 412: One or more conditions in the request headers (If-Match, If-Unmodified-Since) evaluated to false.

4.

You encounter 200 when the most common HTTP response — indicates the request was processed successfully.

5.

You encounter 412 when when using conditional requests with ETags and the resource has changed.

Cuándo usar cada uno

For 200 (OK): No fix needed. The request succeeded as expected. For 412 (Precondition Failed): Refresh the ETag/Last-Modified value and retry with updated preconditions.

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