451
Unavailable For Legal Reasons
Client errors (4xx)·RFC 7725
What 451 means
The resource is unavailable due to legal demands (e.g. censorship or a takedown).
The number references Ray Bradbury’s "Fahrenheit 451". The body should identify the legal authority where possible.
Client errors (4xx)
The request contains an error from the client — bad syntax, missing auth or a wrong URL.
Other 4xx codes
400Bad Request401Unauthorized402Payment Required403Forbidden404Not Found405Method Not Allowed406Not Acceptable407Proxy Authentication Required408Request Timeout409Conflict410Gone411Length Required412Precondition Failed413Content Too Large414URI Too Long415Unsupported Media Type416Range Not Satisfiable417Expectation Failed418I'm a teapot421Misdirected Request422Unprocessable Content423Locked424Failed Dependency425Too Early426Upgrade Required428Precondition Required429Too Many Requests431Request Header Fields Too Large
FAQ — 451
What does HTTP 451 mean?
451 Unavailable For Legal Reasons: The resource is unavailable due to legal demands (e.g. censorship or a takedown). The number references Ray Bradbury’s "Fahrenheit 451". The body should identify the legal authority where possible.
Which class does status code 451 belong to?
451 is a Client errors (4xx) code. The request contains an error from the client — bad syntax, missing auth or a wrong URL.
Where is the 451 code defined?
Status code 451 is defined in RFC 7725 and is part of the IANA HTTP Status Code Registry.