HTTP Error Codes : List and Description

HTTP status codes from a server comes in response on each HTTP request. The server tells client through HTTP status code whether about the request. On failure, the HTTP Error Codes status codes like 404, 403 and 400 tells what do do.

Purpose of this HTTP Error Codes list

There are two standard lists of HTTP Error Codes are available on the Internet – one is W3C and Internet Engineering Task Force. However, they are written as documents making an average user difficult to understand that these HTTP Error Codes means.

You can get these HTTP Error Codes while analyzing through any HTTP header response service or a page with webpagetest.org, where each components will show the HTTP Error Codes if there are any. For example, if the favicon is not uploaded on CDN, but the call is to CDN, quite obviously the header response of the website will not show any of these HTTP Error Codes but if we test on webpagetest.org, the favicon loading will show 404 error. This what Wiki writers forgot / do not know to copy in their HTTP Error Codes list.

List of Common HTTP Error Codes

First before starting the list of HTTP Error Codes, we must mention 100 to 118 denotes processing, 200 to 207 denotes successful operation, 300 to 307 denotes redirection in some way or another.

HTTP Error Codes 4XY denote failure

HTTP Error Codes 4XY, where X is equal to or not equal to Y denotes failure to serve a request of a client, usually through browser.

1. 400 Bad Request : The request was incorrectly done.
2. 401 Unauthorized : Usually set intentionally to SSL protected pages to drive away unauthentic users.
3. 402 Payment Required : Same like above but in this case Payment is required usually which is processed by a third party server like payment gateways.
4. 403 Forbidden : The content is not intended for public usage.
5. 404 Not Found : The requested resource was not found. Most commonly found error.
6. 405 Method Not Allowed : Usually set to drive away non human, script driven requests.
7. 406 Not Acceptable : The content has issues with header.
8. 407 Proxy Authentication Required : Similar to the status 401 is firstly to authenticate the client to use the proxy.
9. 408 Request Time-out : Within the time period allowed by the server cant not a complete client request. Usually it is temporary.
10. 409 Conflict : Primarily it is a set error for protection.
11. 410 Gone : The requested resource is no longer available and has been permanently removed.
12. 411 Length Required : The request can not be processed without a “Content-Length” header field.
13. 412 Precondition Failed : If “If-Match” header field not met; it is thrown.
14. 413 Request Entity Too Large : The query was too large to be processed by the server.
15. 414 Request-URI Too Long : The URI of the request was too long. Cause is often an infinite loop of redirects.
16. 415 Unsupported Media Type : The contents of the request has been submitted with invalid or out of defined media type.
17. 416 Requested range not satisfiable : The requested resource was part of an invalid or is not on the server.
18. 417 Expectation Failed : Used in connection with an “Expect” header field. Located in the “Expect” header field behavior required of the server can not be met.
19. 444 No Response : This is a response from nginx HTTP server to protect the server.

HTTP Error Codes 5XY denote failure too

HTTP Error Codes 5XY, where X is equal to or not equal to Y denotes failure of the server to serve a request, that means there is the requested content, but for some reason it can not be delivered. We have wrote ago about 500 server error.

1. 500 Internal Server Error : This is a collection-status code for unexpected server error.
2. 501 Not Implemented : The functionality to process the request is not available from this server. For example, a cause is unknown or unsupported HTTP method.
3. 502 Bad Gateway : The server could not fulfill its function as a gateway or proxy, as it has in turn received an invalid response.
4. 503 Service Unavailable : The server is temporarily unavailable, for example, due to overloading or maintenance. A “Retry-After ‘header field in the response may indicate the client at a time when the request could be modified if necessary.
5. 504 Gateway Time-out : The server could not fulfill its function as a gateway or proxy, because he has received within a specified period of time no response from his hand, used servers or services.
6. 505 HTTP version not supported : The used version of HTTP (meaning the number before the comma) is not supported by the server or rejected.
7. 507 Insufficient Storage : The request could not be processed because the server disk space it currently is not sufficient.
8. 509 Bandwidth Limit Exceeded : The request was rejected, because otherwise the bandwidth would be exceeded.
9. 510 Not Extended : The request does not contain all information that is waiting for the requested server extension imperative