Unavailable For Legal Reasons

The resource is blocked for legal reasons like a government takedown.

451 Unavailable For Legal Reasons means access is being denied because a law, court order, or government demand says it must be, not because anything is technically broken. The number is a nod to Ray Bradbury's Fahrenheit 451. You'll see it on content geo-blocked by regulation, like some news sites for EU visitors after GDPR, and on takedown-compliant pages.

What 451 looks like on the wire

GET /articles/leaked-report HTTP/1.1
Host: example.com

HTTP/1.1 451 Unavailable For Legal Reasons
Link: <https://legal.example.com/takedowns/2026-041>; rel="blocked-by"

About 4xx Client Error

The request has a problem the client needs to fix, like a bad URL, missing auth, or invalid input.

Where it's defined

451 Unavailable For Legal Reasons is defined in RFC 7725 §3. MDN's 451 reference covers browser behavior and examples.

Looking for a different one? See the full HTTP status code reference.