HTTP 101 Switching Protocols vs 403 Forbidden
HTTP 101 (Switching Protocols) is a 1xx Informational response, while 403 (Forbidden) 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, 403 means that the server understood the request but refuses to authorize it. Unlike 401, authentication will not help — the user simply does not have permission.
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 server understood the request but refuses to authorize it. Unlike 401, authentication will not help — the user simply does not have permission.
このコードが表示される場合
When trying to access a resource you're authenticated for but don't have permission to access.
解決方法
Check your user role/permissions. Contact the admin to request access.
主な違い
101 is a 1xx Informational response, while 403 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 403: The server understood the request but refuses to authorize it. Unlike 401, authentication will not help — the user simply does not have permission.
You encounter 101 when when upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
You encounter 403 when when trying to access a resource you're authenticated for but don't have permission to access.
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 403 (Forbidden): Check your user role/permissions. Contact the admin to request access.