What Is A HTTP Status Code?

Date First Published: 12th April 2022

Topic: Computer Networking

Article Type: Computer Terms & Definitions

Difficulty: Medium

Subtopic: Network Identifiers

Difficulty Level: 5/10

CONTENTS

List Of HTTP Status Codes

Learn more about what a HTTP status code is in this article.

A HTTP status code is a three-digit code that identifies the status of a HTTP request on the World Wide Web. For example, the HTTP status code 404 means that the requested page cannot be found. The official registry of HTTP status codes is maintained by IANA and all HTTP status codes are divided into five categories, with the first digit identifying the category of the HTTP status code.

The categories include:

1xx – Informational. The request was received and the information is being processed.
2xx – Successful. The request was successfully received and accepted.
3xx – Redirection. Further action needs to be taken in order for the request to be completed.
4xx – Client error. The request cannot be processed due to an error on the client-side, such as the page being restricted or not being found.
5xx – Server error. The request cannot be processed due to an error on the server-side, such as the server being unable to handle the request. It is usually caused by errors in Htaccess or PHP files.

List Of HTTP Status Codes

This table contains the list of all HTTP status codes by category.

1xx - Informational

Status Code	Name	Description
100	Continue	Indication of everything so far being okay. The request has only been partially received by the server and the client should continue with the request as long as it has not been denied.
101	Switching Protocols	The server switches protocols. It indicates that the TCP connection is about to be used for a different protocol.
102	Processing	The server has accepted the request but has not processed it yet.
103	Early Hints	Designed to allow the user to preload resources whilst the server prepares a response.

2xx - Success

Status Code	Name	Description
200	Okay	Indicates a successful request with no errors.
201	Created	The request is complete and a new resource has been created.
202	Accepted	The request is accepted for processing, but the processing has not been completed.
203	Non-authoritative Information	The request is successful, but the enclosed payload has been altered by a transforming proxy.
204	No Content	The request has been successfully processed by the server, but no content is being returned.
205	Reset Content	The request has been successfully processed by the server, but no content is being returned. However, this status code indicates that the browser needs to reset the document view, such as clearing the contents of a form.
206	Partial Content	The request is successful and the server is returning partial data of the size requested in response to the range header of a request.
207	Multi-status	This status code contains a number of separate resource codes in situations where multiple resource codes are appropriate.
208	Already reported	A status code used inside the response element DAV (propstat) in order to avoid listing the internal members of several bindings to the exact same collection over and over again.
226	IM Used	The server has completed a GET request for the resource and the resource represents the result of one or more instance-manipulations that are applied to the current instance.

3xx - Redirection

Status Code	Name	Description
300	Multiple Choices	Indicates that the request has multiple responses and the client must choose one. It is a link list where the user can select a link and go to that location.
301	Moved Permanently	The requested page has been moved to a new URL.
302	Found	The requested page has been temporarily moved to a new URL.
303	See Other	The requested page is available at a different URL. It gives the client instructions to issue a GET request on the new URL.
304	Not Modified	The requested page has not been modified since the last time it was accessed. It is used for caching purposes, which eliminates the need for the same information to be downloaded from the web server over and over again.
305	Use Proxy	The requested page must be accessed through a proxy.
306	Switch Proxy	This HTTP status code is no longer used. Originally, it meant that future requests should use the specified proxy.
307	Temporary Redirect	Has similar behaviour to status code 302. The requested page has been temporarily moved to a new URL. It means that the redirect is temporary and future requests should still use the original URL.
308	Permanent Redirect	Has similar behaviour to status code 301. The requested page has been moved to a new URL. It means that all future requests must use the new URL.

4xx - Client errors

Status Code	Name	Description
400	Bad request	The server was unable to process the request sent from the browser due to an error on the client-side, such as size too large or invalid request syntax.
401	Unauthorised	The requested page requires authorisation and is not accessible without a username and password.
402	Payment Required	This HTTP status code is reserved for future use. It might be used when an account does not have sufficient funds to perform an action.
403	Forbidden	The server understood the request, but access is denied to the requested page due to permission errors.
404	Not Found	The requested page cannot be found on the server.
405	Method Not Acceptable	The server does not allow the request method used for the resource.
406	Not Acceptable	The client has requested a response using accept headers that the server is unable to fulfil.
407	Proxy Authentication Required	The client must authenticate with a proxy server before the request is fulfilled.
408	Request Timeout	The client made a request that took longer than the server was prepared to wait
409	Conflict	The request could not be processed by the server due to a conflict related to the page.
410	Gone	The requested page is no longer available, never going to return, and has no redirect.
411	Length Required	The 'content-length' was not specified, causing the server to not accept the request.
412	Precondition Failed	The server failed to meet one of the preconditions that the requester put in the request header fields.
413	Payload Too Large	The request is larger than the server can handle.
414	Request URL Too Long	The server denied the request because the URL was too long for it to process.
415	Unsupported Media Type	The server denied the request because the media type was unsupported.
416	Range Not Satisfiable	The client requested a byte range, but that range is unavailable and the server cannot supply it.
417	Expectation Failed	The expectation that was provided in an Expect request-header field could not be met by the server.
421	Misdirected Request	The request was directed at a server that was unable to produce a response.
422	Unprocessable Entity	The server could not process the instructions of a well-formed request.
423	Locked	The requested resource was locked.
424	Failed Dependency	The client's request failed because it depended on another request that had previously failed.
425	Too Early	The server is unwilling to process a request that might be replayed.
426	Upgrade Required	The server refused to handle the request using the current protocol, but will accept the request after the client upgrades to a different protocol.
428	Precondition Required	The server requires the request to be conditional.
429	Too Many Requests	The client has sent too many requests in a given period of time.
431	Request Header Fields Too Large	The server refused to fulfil the client requests because the HTTP headers are too large.
451	Unavailable For Legal Reasons	The client is denied access to a page due to legal reasons, such as a webpage censored by the government.

5xx - Server errors

Status Code	Name	Description
500	Internal Server Error	The server encountered something unexpected that prevented it from displaying the page.
501	Not Implemented	The server does not have the facilities or capabilities to handle the request.
502	Bad Gateway	The server acting as a gateway received an invalid response from the upstream server whilst trying to fulfil the request.
503	Service Unavailable	The request was not completed due to the server being temporarily down, usually due to it being overloaded or maintenance.
504	Gateway Timeout	The server acting as a gateway ran out of time to wait for a server response.
505	HTTP Version Not Supported	The server does not support the HTTP version used in the request.
508	Loop Detected	An infinite loop was detected by the server whilst processing the request.
510	Not Extended	Additional extensions are required in order for the server to fulfil the request.
511	Network Authentication Required	The client needs to authenticate in order to gain network access.