HTTP status codes Explained


What Are Http Error Codes?

When visiting a Web sites(Web application) on a Browser, we try to access content present on a web server. The client application makes connections to Web servers via a network protocol called HTTP.
The Request sent by Browser to Web Server Is called HTTP request. The Response sent by web server to web Browser is called HTTP Response.

Every HTTP request that is received by a server is responded to with an HTTP status code. HTTP status codes are 3 digit codes, where the first digit of the Status-Code defines the class of response and the last two digits do not have any categorization role.
The class of a status code can be quickly identified by its first digit:

S.N.Code and Description
11xx: Informational- It means the request has been received and the process is continuing.
22xx: Success- It means the action was successfully received, understood, and accepted.
33xx: Redirection- It means further action must be taken in order to complete the request.
44xx: Client Error- It means the request contains incorrect syntax or cannot be fulfilled.
55xx: Server Error- It means the server failed to fulfill an apparently valid request.

Given below is a list of status codes along with description.

1xx: Information

100 ContinueOnly a part of the request has been received by the server, but as long as it has not been rejected, the client should continue with the request.
101 Switching ProtocolsThe server switches protocol.

2xx: Successful

200 OKThe request is OK.
201 CreatedThe request is complete, and a new resource is created .
202 AcceptedThe request is accepted for processing, but the processing is not complete.
203 Non-authoritative InformationThe information in the entity header is from a local or third-party copy, not from the original server.
204 No ContentA status code and a header are given in the response, but there is no entity-body in the reply.
205 Reset ContentThe browser should clear the form used for this transaction for additional input.
206 Partial ContentThe server is returning partial data of the size requested. Used in response to a request specifying a Range header. The server must specify the range included in the response with the Content-Range header.

3xx: Redirection

300 Multiple ChoicesA link list. The user can select a link and go to that location. Maximum five addresses  .
301 Moved PermanentlyThe requested page has moved to a new url .
302 FoundThe requested page has moved temporarily to a new url .
303 See OtherThe requested page can be found under a different url .
304 Not ModifiedThis is the response code to an If-Modified-Since or If-None-Match header, where the URL has not been modified since the specified date.
305 Use ProxyThe requested URL must be accessed through the proxy mentioned in the Location header.
306 UnusedThis code was used in a previous version. It is no longer used, but the code is reserved.
307 Temporary RedirectThe requested page has moved temporarily to a new url.

4xx: Client Error

400 Bad RequestThe server did not understand the request.
401 UnauthorizedThe requested page needs a username and a password.
402 Payment RequiredYou can not use this code yet.
403 ForbiddenAccess is forbidden to the requested page.
404 Not FoundThe server can not find the requested page.
405 Method Not AllowedThe method specified in the request is not allowed.
406 Not AcceptableThe server can only generate a response that is not accepted by the client.
407 Proxy Authentication RequiredYou must authenticate with a proxy server before this request can be served.
408 Request TimeoutThe request took longer than the server was prepared to wait.
409 ConflictThe request could not be completed because of a conflict.
410 GoneThe requested page is no longer available .
411 Length RequiredThe “Content-Length” is not defined. The server will not accept the request without it .
412 Precondition FailedThe pre condition given in the request evaluated to false by the server.
413 Request Entity Too LargeThe server will not accept the request, because the request entity is too large.
414 Request-url Too LongThe server will not accept the request, because the url is too long. Occurs when you convert a “post” request to a “get” request with a long query information .
415 Unsupported Media TypeThe server will not accept the request, because the mediatype is not supported .
416 Requested Range Not SatisfiableThe requested byte range is not available and is out of bounds.
417 Expectation FailedThe expectation given in an Expect request-header field could not be met by this server.

5xx: Server Error

500 Internal Server ErrorThe request was not completed. The server met an unexpected condition.
501 Not ImplementedThe request was not completed. The server did not support the functionality required.
502 Bad GatewayThe request was not completed. The server received an invalid response from the upstream server.
503 Service UnavailableThe request was not completed. The server is temporarily overloading or down.
504 Gateway TimeoutThe gateway has timed out.
505 HTTP Version Not SupportedThe server does not support the “http protocol” version.


Now that you are familiar with the most common HTTP error codes.