HTTP Status Code

Whenever you visit a web page, your computer will request data from a server through HTTP. Even before the requested page is displayed in your browser, the web server will send the HTTP header that has the status code. The status code provides information about the status of the request. A normal web page gets the status code as 200. But we do not see this as the server proceeds to send the contents of the page.

Origin of Status Codes

As a part of the HTTP 0.9 specifications, the World Wide Web Consortium (W3C) established HTTP status codes in 1992. Tim Berners-Lee, who invented the web and the first web browser in 1990, defined the status codes.

List of Status Codes 

A brief overview of HTTP status codes is given below.

Code
Meaning
Description
100
Continue
Confirms the client about the arrival of the first part of the request and informs to continue with the rest of the request or ignore if the request has been fulfilled
101
Switching Protocols
Informs the client about the server switching the protocols to that specified in the Upgrade message header field during the current connection.
200
OK
Standard response for successful requests
201
Created
Request fulfilled and new resource created
202
Accepted
Request accepted, but not yet processed
203
Non-Authoritative Information
Returned meta information was not the definitive set from the origin server.
204
No Content
Request succeeded without requiring the return of an entity-body
205
Reset Content
Request succeeded but require resetting of the document view that caused the request
206
Partial Content
Partial GET request was successful
300
Multiple Choices
Requested resource has multiple choices at different locations.
301
Moved Permanently
Resource permanently moved to a different URL.
302
Found
Requested resource was found under a different URL but the client should continue to use the original URL.
303
See Other
Requested response is at a different URL and can be accessed only through a GET command.
304
Not Modified
Resource not modified since the last request.
305
Use Proxy
Requested resource should be accessed through the proxy specified in the location field.
306
No Longer Used
Reserved for future use
307
Temporary Redirect
Resource has been moved temporarily to a different URL.
400
Bad Request
Syntax of the request not understood by the server.
401
Not Authorized
Request requires user authentication
402
Payment Required
Reserved for future use.
403
Forbidden
Server refuses to fulfill the request.
404
Not Found
Document or file requested by the client was not found.
405
Method Not Allowed
Method specified in the Request-Line was not allowed for the specified resource.
406
Not Acceptable
Resource requested generates response entities that has content characteristics not specified in the accept headers.
407
Proxy Authentication Required
Request requires the authentication with the proxy.
408
Request Timeout
Client fails to send a request in the time allowed by the server.
409
Conflict
Request was unsuccessful due to a conflict in the state of the resource.
410
Gone
Resource requested is no longer available with no forwarding address
411
Length Required
Server doesn’t accept the request without a valid Content-Length header field.
412
Precondition Failed
Precondition specified in the Request-Header field returns false.
413
Request Entity Too Large
Request unsuccessful as the request entity is larger than that allowed by the server
414
Request URL Too Long
Request unsuccessful as the URL specified is longer than the one, the server is willing to process.
415
Unsupported Media Type
Request unsuccessful as the entity of the request is in a format not supported by the requested resource
416
Requested Range Not Satisfiable
Request included a Range request-header field without any range-specifier value
417
Expectation Failed
Expectation given in the Expect request-header was not fulfilled by the server.
422
Unprocessable Entity
Request well-formed but unable to process because of semantic errors
423
Locked
Resource accessed was locked
424
Failed Dependency
Request failed because of the failure of a previous request
426
Upgrade Required
Client should switch to Transport Layer Security
500
Internal Server Error
Request unsuccessful because of an unexpected condition encountered by the server.
501
Not Implemented
Request unsuccessful as the server could not support the functionality needed to fulfill the request.
502
Bad Gateway
Server received an invalid response from the upstream server while trying to fulfill the request.
503
Service Unavailable
Request unsuccessful to the server being down or overloaded.
504
Gateway Timeout
Upstream server failed to send a request in the time allowed by the server.
505
HTTP Version Not Supported
Server does not support the HTTP version specified in the request.