This is a list of
Hypertext Transfer Protocol
The Hypertext Transfer Protocol (HTTP) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web, w ...
(HTTP) response status codes. Status codes are issued by a server in response to a
client's request made to the server. It includes codes from IETF
Request for Comments
A Request for Comments (RFC) is a publication in a series from the principal technical development and standards-setting bodies for the Internet, most prominently the Internet Engineering Task Force (IETF). An RFC is authored by individuals or ...
(RFCs), other specifications, and some additional codes used in some common applications of the HTTP. The first digit of the status code specifies one of five standard classes of responses. The optional message phrases shown are typical, but any human-readable alternative may be provided, or none at all.
Unless otherwise stated, the status code is part of the HTTP standard ().
The
Internet Assigned Numbers Authority
The Internet Assigned Numbers Authority (IANA) is a standards organization that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System (DNS), media types, and other Internet ...
(IANA) maintains the official registry of HTTP status codes.
All HTTP response status codes are separated into five classes or categories. The first digit of the status code defines the class of response, while the last two digits do not have any classifying or categorization role. There are five classes defined by the standard:
* ''1xx informational response'' – the request was received, continuing process
* ''2xx successful'' – the request was successfully received, understood, and accepted
* ''3xx redirection'' – further action needs to be taken in order to complete the request
* ''4xx client error'' – the request contains bad syntax or cannot be fulfilled
* ''5xx server error'' – the server failed to fulfil an apparently valid request
1xx informational response
An informational response indicates that the request was received and understood. It is issued on a provisional basis while request processing continues. It alerts the client to wait for a final response. The message consists only of the status line and optional header fields, and is terminated by an empty line. As the HTTP/1.0 standard did not define any 1xx status codes, servers
[Emphasised words and phrases such as and represent interpretation guidelines as given by RFC 2119] send a 1xx response to an HTTP/1.0 compliant client except under experimental conditions.
;100 Continue
: The server has received the request headers and the client should proceed to send the request body (in the case of a request for which a body needs to be sent; for example, a