The HyperText Transfer Protocol (HTTP) 451 Unavailable For Legal Reasons client error response code indicates that the user requested a resource that is not available due to legal reasons, such as a web page for which a legal action has been issued.
451 Unavailable For Legal Reasons
This example response is taken from the IETF RFC (see below) and contains a reference to Monty Python's Life of Brian.
Note: the Link header might also contain a rel="blocked-by" relation identifying the entity and implementing blockage, not any other entity mandating it.
Any attempt to identify the entity ultimately responsible for the resource being unavailable, such as the name of the person or organization that made a legal demand resulting in the content's removal belongs in the response body, not in the rel="blocked-by" link.
HTTP/1.1 451 Unavailable For Legal Reasons Link: <https://spqr.example.org/legislatione>; rel="blocked-by" Content-Type: text/html
<html>
<head><title>Unavailable For Legal Reasons</title></head>
<body>
<h1>Unavailable For Legal Reasons</h1>
<p>This request may not be serviced in the Roman Province
of Judea due to the Lex Julia Majestatis, which disallows
access to resources hosted on servers deemed to be
operated by the People's Front of Judea.</p>
</body>
</html> | Specification | Title |
|---|---|
| RFC 7725: 451 Unavailable For Legal Reasons | An HTTP Status Code to Report Legal Obstacles |
The information shown below has been pulled from MDN's GitHub (https://github.com/mdn/browser-compat-data).
| Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
| Basic support | Yes | Yes | Yes | Yes | Yes | Yes |
| Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS Safari |
|---|---|---|---|---|---|---|---|
| Basic support | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/451