HTTP Status Codes

HTTP Status Codes

HTTP status codes are returned by web servers to indicate the status of a request. The status code is a 3-digit code indicating the particular response. The first digit of this code identifies the class of the status code. The remaining 2 digits correspond to the specific condition within the response class. The following table outlines all status codes defined for the HTTP/1.1 

• 1xx - informational
• 2xx - successful
• 3xx - redirection
• 4xx - client error 
• 5xx - server error 

1xx class - Informational
Informational status codes are provisional responses from the web server... they give the client a heads-up on what the server is doing. Informational codes do not indicate an error condition. 
 

100	Continue The continue status code tells the browser to continue sending a request to the server.
101	Switching Protocols The server sends this response when the client asks to switch from HTTP/1.0 to HTTP/1.1

2xx class - Successful
This class of status code indicates that the client's request was received, understood, and successful. 
 

200	Successful
201	Created
202	Accepted
203	Non-Authorative Information
204	No Content
205	Reset Content
206	Partial Content The partial content success code is issued when the server fulfills a partial GET request. This happens when the client is downloading a multi-part document or part of a larger file.

3xx class - Redirection
This code tells the client that the browser should be redirected to another URL in order to complete the request. This is not an error condition. 
 

300	Multiple Choices
301	Moved Permanently
302	Moved Temporarily
303	See Other
304	Not Modified
305	Use Proxy
307	Temporary Redirect

4xx class - Client Error
This status code indicates that the client has sent bad data or a malformed request to the server. Client errors are generally issued by the webserver when a client tries to gain access to a protected area using a bad username and password. 
 

400	Bad Request
401	Unauthorized
402	Payment Required
403	Forbidden
404	Not Found
405	Method Not Allowed
406	Not Acceptable
407	Proxy Authentication Required
408	Request Timeout
409	Conflict
410	Gone
411	Length Required
412	Precondition Failed
413	Request Entity Too Long
414	Request-URI Too Long
415	Unsupported Media Type

5xx class - Server Error
This status code indicates that the client's request couldn't be succesfully processed due to some internal error in the web server. These error codes may indicate something is seriously wrong with the web server. 
 

500	Internal Server Error An internal server error has caused the server to abort your request. This is an error condition that may also indicate a misconfiguration with the web server. However, the most common reason for 500 server errors is when you try to execute a script that has syntax errors.
501	Not Implemented This code is generated by a webserver when the client requests a service that is not implemented on the server. Typically, not implemented codes are returned when a client attempts to POST data to a non-CGI (ie, the form action tag refers to a non-executable file).
502	Bad Gateway The server, when acting as a proxy, issues this response when it receives a bad response from an upstream or support server.
503	Service Unavailable The web server is too busy processing current requests to listen to a new client. This error represents a serious problem with the webserver (normally solved with a reboot).
504	Gateway Timeout Gateway timeouts are normally issued by proxy servers when an upstream or support server doesn't respond to a request in a timely fashion.
505	HTTP Version Not Supported The server issues this status code when a client tries to talk using an HTTP protocol that the server doesn't support or is configured to ignore.