Client

HTTP Status Code 451 indicates Unavailable For Legal Reasons, which means that the server is denying access to the resource due to legal restrictions. When a server responds with HTTP Status Code 451, it signifies that the requested resource is not available because of laws or regulations that prohibit access to that content. This status code is particularly relevant in cases where content has been removed or blocked due to censorship, copyright issues, or other legal constraints.

HTTP Status Code 431 indicates Request Header Fields Too Large which means that the server is unable to process the request due to the size of one or more request header fields exceeding its limits. This status code falls under the Client Error category, alerting the client that their request cannot be fulfilled as is.

HTTP Status Code 429 signifies Too Many Requests indicating that the user has sent too many requests in a given amount of time. This status code is a part of the Client Error category and is typically used to inform the client that they have exceeded the rate limits set by the server. Rate limiting is commonly implemented to prevent abuse, such as spamming or overwhelming the server with requests, which can lead to performance degradation for all users.

HTTP Status Code 428 indicates that a precondition required for the request is not met. This status code is part of the Client Error class and is used in situations where a conditional request was made, but the server cannot fulfill it due to the specified precondition being absent or false. Typically, this status code is employed in contexts involving conditional requests where the client expects a specific condition to be satisfied before proceeding with the operation.

HTTP Status Code 426 refers to Upgrade Required. This status code indicates that the server refuses to perform the requested operation using the current protocol, but it can be upgraded to a different protocol that is supported by the server.

HTTP Status Code 425 refers to Too Early. This status code indicates that the server is unwilling to risk processing a request that might be replayed due to its early nature.

HTTP Status Code 424 refers to Failed Dependency. This status code indicates that the request failed because it depended on another request that also failed.

HTTP Status Code 423 refers to Locked. This status code indicates that the resource that is being accessed is currently locked and cannot be modified.

HTTP Status Code 422 refers to Unprocessable Entity. This status code indicates that the server understands the content type of the request entity and the syntax is correct, but it was unable to process the contained instructions.

HTTP Status Code 421 refers to Misdirected Request. This status code indicates that the server is unable to produce a response for the request because the request was directed to a server that is not able to produce a response for that specific request.