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451 Unavailable For Legal Reasons

HTTP 451 Unavailable For Legal Reasons. The resource is unavailable because of a legal demand — e.g. a court order or government censorship. The number references Ray Bradbury's Fahrenheit 451. When to use it: Return when access is denied for legal reasons; the response should explain the legal demand where possible. It is a client-error (4xx) status, which means the problem is with the request and the caller must change something before retrying. (Reference: RFC 7725.)

Quick answer

The resource is unavailable because of a legal demand — e.g. a court order or government censorship. The number references Ray Bradbury's Fahrenheit 451.

  • When to use: Return when access is denied for legal reasons; the response should explain the legal demand where possible.
  • No fix needed — Unavailable For Legal Reasons is not an error to resolve on the client side.
  • Reference: RFC 7725
  • Category: 4xx Client Error
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Frequently asked questions

What does HTTP 451 mean?

HTTP 451 Unavailable For Legal Reasons: The resource is unavailable because of a legal demand — e.g. a court order or government censorship. The number references Ray Bradbury's Fahrenheit 451. It is a client-error (4xx) status, which means the problem is with the request and the caller must change something before retrying. It is defined in RFC 7725.

What is the difference between 451 and 403?

451 Unavailable For Legal Reasons is a specialised refusal: the resource is blocked because of a legal demand such as a court order or government censorship, and the response should explain the demand where possible. 403 Forbidden is a general "not allowed" with no legal connotation. Use 451 specifically to signal that a legal obligation — not an ordinary permission check — is the reason for denial.

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