Feilresponskoder

Feilresponskoder, often referred to as HTTP status codes, are standardized three-digit numbers returned by a web server to indicate the outcome of a client's request. These codes are crucial for understanding the communication between a web browser or application and the server. They are grouped into five classes, each designated by the first digit of the code.

Class 1xx codes are informational, meaning the request was received and is being processed. This category is rarely seen by end-users.

Class 2xx codes indicate success. The most common is 200 OK, signifying that the request has been successfully received, understood, and accepted. Other 2xx codes include 201 Created, used when a resource is successfully created, and 204 No Content, indicating the server fulfilled the request but there is no content to send back.

Class 3xx codes are for redirection. They inform the client that further action needs to be taken to complete the request, usually by making another request to a different URI. 301 Moved Permanently and 302 Found are common examples.

Class 4xx codes denote client errors. This means the server believes the client made a mistake. The most frequent is 404 Not Found, indicating the requested resource could not be found on the server. Other examples include 400 Bad Request, for general client-side errors, and 401 Unauthorized, for authentication issues.

Class 5xx codes signify server errors. These codes mean the server failed to fulfill an apparently valid request due to an error on the server's side. 500 Internal Server Error is a generic message indicating that something went wrong on the server. 503 Service Unavailable suggests the server is temporarily unable to handle the request. Understanding these codes is essential for web developers and system administrators to diagnose and resolve issues.