HTTP 200 OK vs 428 Precondition Required
HTTP 200 (OK) is a 2xx Success response, while 428 (Precondition Required) 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, 428 means that the server requires the request to be conditional (e.g., include If-Match header) to prevent lost updates.
説明
The request succeeded. The meaning depends on the HTTP method: GET returns the resource, POST reports the action result, HEAD returns headers only.
このコードが表示される場合
The most common HTTP response — indicates the request was processed successfully.
解決方法
No fix needed. The request succeeded as expected.
説明
The server requires the request to be conditional (e.g., include If-Match header) to prevent lost updates.
このコードが表示される場合
When an API requires optimistic concurrency control via ETags.
解決方法
Fetch the resource first to get its ETag, then include If-Match in your update request.
主な違い
200 is a 2xx Success response, while 428 is a 4xx Client Error response.
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.
HTTP 428: The server requires the request to be conditional (e.g., include If-Match header) to prevent lost updates.
You encounter 200 when the most common HTTP response — indicates the request was processed successfully.
You encounter 428 when when an API requires optimistic concurrency control via ETags.
どちらをいつ使うか
For 200 (OK): No fix needed. The request succeeded as expected. For 428 (Precondition Required): Fetch the resource first to get its ETag, then include If-Match in your update request.