HTTP 101 Switching Protocols vs 451 Unavailable For Legal Reasons
HTTP 101 (Switching Protocols) is a 1xx Informational response, while 451 (Unavailable For Legal Reasons) 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, 451 means that the server is denying access to the resource as a consequence of a legal demand. Named after Ray Bradbury's Fahrenheit 451.
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 is denying access to the resource as a consequence of a legal demand. Named after Ray Bradbury's Fahrenheit 451.
このコードが表示される場合
When content is blocked due to court orders, GDPR requests, or government censorship.
解決方法
No technical fix. The block is legally mandated. Contact the site operator for details.
主な違い
101 is a 1xx Informational response, while 451 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 451: The server is denying access to the resource as a consequence of a legal demand. Named after Ray Bradbury's Fahrenheit 451.
You encounter 101 when when upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
You encounter 451 when when content is blocked due to court orders, GDPR requests, or government censorship.
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 451 (Unavailable For Legal Reasons): No technical fix. The block is legally mandated. Contact the site operator for details.