These are the weirdest http status codes

451 Status Code : Unavailable for Legal Reasons

The 451 status code is an HTTP status code that was introduced to indicate that a web page or resource is unavailable for legal reasons. It is often used when a website or web server is required by law to restrict access to certain content, typically due to government censorship or legal issues.

Here’s the official definition of the 451 status code from RFC 7725, which introduced it:

451 Unavailable For Legal Reasons

The 451 status code is used to indicate that the server is denying access to the resource as a consequence of a legal demand.

The server SHOULD include an explanation of the error situation, and whether it is a temporary or permanent condition.

The 451 status code is intended to be machine-readable. The representation includes information that will help the client understand the nature of the legal demand. A 451 response is cacheable by default; i.e., unless otherwise indicated by the method definition or explicit cache controls.

A 451 response is not a guarantee that accessing the resource is legal everywhere. It is the responsibility of the user to obey relevant laws and regulations and confirm compliance with them.

218 Status Code: This is Fine

HTTP response status code 218 This is fine is an unofficial HTTP response that is used specifically by the Apache Web Server. It is used as a catch-all error condition that allows the passage of a message body through Apache when the ProxyErrorOverride setting is enabled.

HTTP response status code 218 This is fine is sent by Apache to indicate that there is an HTTP client error or HTTP server error, but this special status code communicating success is used to maintain a standardized look and feel by the client.

420 Status Code: Enhance Your Calm

The HTTP response status codes 420 Method Failure and 420 Enhance your calm is an unofficial client error that is returned by the server to indicate a client error.

The 420 Enhance Your Calm status code is an unofficial extension by Twitter. Twitter used this to tell HTTP clients that they were being rate limited. Rate limiting means putting restrictions on the total number of requests a client may do within a time period.

418 Status Code: I’m a teapot

The HTTP 418 I’m a teapot client error response code indicates that the server refuses to brew coffee because it is, permanently, a teapot. A combined coffee/tea pot that is temporarily out of coffee should instead return 503. This error is a reference to Hyper Text Coffee Pot Control Protocol defined in April Fools’ jokes in 1998 and 2014.