451 HTTP Response Status Code Definition: Example, Usage, Methods

The 451 HTTP Status Code means that the request is unavailable for legal reasons indicates that as a result of a legal demand, the server is limiting access to the resource. It is possible that the server in issue is not an origin server. Typically, this form of legal demand has the greatest direct impact on the operations of ISPs and search engines. Responses to this Status Code should include an explanation of the legal demand’s contents in the answer body, including the party who made it, the applicable legislation or regulation, and the types of person and resource to whom it applies. The 451 HTTP Status Code does not imply the existence or non-existence of the resource specified in the request. That is, even if the legal requirements are removed, a request for the resource may still be refused. Clients can often still access the blocked resource by utilizing technical countermeasures such as a VPN or the Tor network. By default, a 451 HTTP Status Code is cacheable, unless the method specification or explicit cache settings indicate otherwise. The difference between 400 HTTP Status Codes and 451 HTTP Status Code is that the 400 HTTP Status Codes indicate that the server is unable or unwilling to perform the request as a result of an apparent client error, whereas the 451 HTTP Status Code indicates that a server operator has received a legal demand requiring them to refuse access to a resource or a collection of resources that contains the requested resource.

What does 451 HTTP Status Code Mean?

The 451 HTTP Status Code means unavailable for legal reasons indicates that the server is limiting access to the resource as a result of a legal demand. It’s possible that this isn’t an origin server at all. ISPs and search engines are the main recipients of this type of legal demand.

How to Use 451 HTTP Status Code for a Website?

To use the 451 HTTP Status Code is when the resource named in the request does not exist or does not exist. That means, it is feasible that even if the legal requirements were removed, the request for the resource might still reject.

How to Check 451 HTTP Status Code?

To check the 451 HTTP Status Code use the web browser network tab and developer tools for every resource that the client uses.

Which HTTP Method is used with 451 HTTP Status Code?

The HTTP methods that are used with the 451 HTTP Status Codes are given below. 

  • HEAD HTTP Method: The HEAD HTTP method is used in the 451 HTTP Response Status Code. The HEAD method requests a response identical to that of the GET method, but without the content of the answer.
  • POST HTTP Method: The POST HTTP method is used in the 451 HTTP Response Status Code. The POST method sends an entity to the resource that was chosen. This can change the server’s state or have other effects.

There is a related HTTP Response Header with 451  HTTP Status Code which is the 431 HTTP Status Code. The 431 HTTP Status Code indicates that the request’s header fields are too large, and the server refuses to handle it. Reducing the request header fields’ size allows the request to be resubmitted.

What are the Browsers Compatibility of 451 HTTP Status Code?

You can see the table that shows the browser’s compatibility of the 451 HTTP Status Code below. 

Browsers NameBrowser Compatibility of 451 HTTP Status Code
ChromeYES
EdgeYES
FirefoxYES
Internet ExplorerYES
OperaYES
SafariYES
Webview AndroidYES

What are the other Similar Status Codes to 451 HTTP Status Codes?

There are other similar HTTP Status Codes to the 451 HTTP Status Code. The following are listed below.

  • 426 Upgrade Required HTTP Status Code: The 426  HTTP Status Code is similar to the 451 HTTP Status Code because they are both client error responses. The 426  HTTP Status Code indicates that the server declines to process the request using the current protocol but may do so if the client upgrades to a different protocol. In a 426 response, the server includes an Upgrade header to indicate the required protocols.
  • 428 Precondition Required HTTP Status Code: The 428  HTTP Status Code is similar to the 451 HTTP Status Code because they are both client error responses. The 428  HTTP Status Code indicates that the origin server expects a conditional request. 
  • 429 Too Many Requests HTTP Status Code: The 429  HTTP Status Code is similar to the 451 HTTP Status Code because they are both client error responses. The 429  HTTP Status Code indicates that too many requests have been made in a short period of time by the user (rate limiting).
  • 425 Too Early HTTP Status Code: This indicates that the server is unwilling to take the risk of processing a request that could be replayed. The 425 HTTP Status Code is similar to the 426 HTTP Status Code which is also a client error response.
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451 HTTP Response Status Code Definition: Example, Usage, Methods

by Holistic SEO time to read: 3 min
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