HTTP 100 Continue vs 451 Unavailable For Legal Reasons
HTTP 100 (Continue) is a 1xx Informational response, while 451 (Unavailable For Legal Reasons) is a 4xx Client Error response. 100 indicates that the server has received the request headers and the client should proceed to send the request body. This lets the client know it can continue with the request or abort if the headers were rejected. 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.
Description
The server has received the request headers and the client should proceed to send the request body. This lets the client know it can continue with the request or abort if the headers were rejected.
Quand vous le voyez
When a client sends an Expect: 100-continue header, the server responds with 100 before the client sends the body.
Comment résoudre
This is an interim response — no fix needed. The client should continue sending the request body.
Description
The server is denying access to the resource as a consequence of a legal demand. Named after Ray Bradbury's Fahrenheit 451.
Quand vous le voyez
When content is blocked due to court orders, GDPR requests, or government censorship.
Comment résoudre
No technical fix. The block is legally mandated. Contact the site operator for details.
Différences clés
100 is a 1xx Informational response, while 451 is a 4xx Client Error response.
HTTP 100: The server has received the request headers and the client should proceed to send the request body. This lets the client know it can continue with the request or abort if the headers were rejected.
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 100 when when a client sends an Expect: 100-continue header, the server responds with 100 before the client sends the body.
You encounter 451 when when content is blocked due to court orders, GDPR requests, or government censorship.
Quand utiliser lequel
For 100 (Continue): This is an interim response — no fix needed. The client should continue sending the request body. For 451 (Unavailable For Legal Reasons): No technical fix. The block is legally mandated. Contact the site operator for details.