HTTP Code¶
HTTP status codes are three-digit numeric codes that are returned by web servers to indicate the outcome of a client’s request to a server. These codes are a part of the HTTP standard and provide information about the status of the request and the server’s response. HTTP status codes are grouped into different ranges, each with a specific meaning.
Here are some of the most common HTTP status codes and their general meanings:
1xx Informational:
100 Continue: the server has received the request headers and the client should proceed to send the request body. 101 Switching Protocols: the server is switching protocols according to the client’s request. 102 Processing: the server has received the request and is processing it, but no response is available yet. 103 Early Hints: this status code is used to return some response headers before final HTTP message.
2xx Successful:
200 OK: the request was successful, and the server has returned the requested resource. 201 Created: the request was successful, and a new resource was created as a result. 202 Accepted: the request has been accepted for processing, but the processing has not been completed. 202 Non-Authoritative Information: the server is a transforming proxy, such as a Web accelerator, that received a 200 OK from its origin, but is returning a modified version of the origin’s response. 204 No Content: the server has successfully processed the request, but there is no content to send in the response.
3xx Redirection:
301 Moved Permanently: the requested resource has been permanently moved to a new location. 302 Found: the requested resource has been temporarily moved to a different location. 303 See Other: the requested resource has been temporarily moved to a different location. 304 Not Modified: the client’s cached version of the resource is still valid; no content is returned.
4xx Client Error:
400 Bad Request: the request from the client was malformed or invalid. 401 Unauthorized: authentication is required, and the client needs to provide valid credentials. 402 Payment Required: reserved for future use. 403 Forbidden: the client does not have permission to access the requested resource. 404 Not Found: the requested resource was not found on the server. 405 Method Not Allowed: a request method is not supported for the requested resource.
5xx Server Error:
500 Internal Server Error: the server encountered an error while processing the request. 501 Not Implemented: the server either does not recognize the request method, or it lacks the ability to fulfil the request. 502 Bad Gateway: the server, while acting as a gateway or proxy, received an invalid response from an upstream server. 503 Service Unavailable: the server is currently unable to handle the request due to temporary overloading or maintenance of the server. 504 Gateway Timeout: the server, while acting as a gateway or proxy, did not receive a timely response from an upstream server. 505 HTTP Version Not Supported: the server does not support the HTTP version used in the request.
See also http_response_code and How to send HTTP response code in PHP?.
Related : Hyper Text Transfer Protocol (HTTP), Response, HTTP Request Headers, REST API, Redirect
