HTTP 101 Switching Protocols vs 405 Method Not Allowed
HTTP 101 (Switching Protocols) is a 1xx Informational response, while 405 (Method Not Allowed) is a 4xx Client Error response. 101 indicates that the server understands the Upgrade header field request and indicates which protocol it is switching to. In contrast, 405 means that the HTTP method is not allowed for the requested resource. The response includes an Allow header listing valid methods.
説明
The server understands the Upgrade header field request and indicates which protocol it is switching to.
このコードが表示される場合
When upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
解決方法
This is normal behavior during protocol upgrades. Ensure your client supports the target protocol.
説明
The HTTP method is not allowed for the requested resource. The response includes an Allow header listing valid methods.
このコードが表示される場合
When sending POST to a read-only endpoint, or DELETE to a non-deletable resource.
解決方法
Check the Allow response header for supported methods. Use the correct HTTP method.
主な違い
101 is a 1xx Informational response, while 405 is a 4xx Client Error response.
HTTP 101: The server understands the Upgrade header field request and indicates which protocol it is switching to.
HTTP 405: The HTTP method is not allowed for the requested resource. The response includes an Allow header listing valid methods.
You encounter 101 when when upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
You encounter 405 when when sending POST to a read-only endpoint, or DELETE to a non-deletable resource.
どちらをいつ使うか
For 101 (Switching Protocols): This is normal behavior during protocol upgrades. Ensure your client supports the target protocol. For 405 (Method Not Allowed): Check the Allow response header for supported methods. Use the correct HTTP method.