HTTP status codes reference

The requested URL corresponds to more than one resource, and the robot failed to determine to which page it refers (code 300 Multiple Choices).

Fix the headers and specify the resource correctly, the robot then will be able to index the page.

The document isn't used by the server and link redirects to another page (code 301 Moved Permanently).

As the users won't see such documents, it doesn't make sense to show them in the search, so the robot doesn't index them. However, the robot will index the redirect target page, if it's available.

The requested resource is temporarily located under another address (code 302 Found).

As the users won't see such documents, it doesn't make sense to show them in the search, so the robot doesn't index them. However, the robot will index the redirect target page, if it's available.

The requested resource resides under a different URL and should be requested with the GET method (code 303 See Other). For the page to be in the search, it must respond with the 200 code.

Code 304 Not Modified. Respond with this code if the page hasn't changed since the last visit by the robot. This will speed up indexing and reduce the traffic.

The requested resource can be accessed only through the proxy server specified in the Location header (code 305 Use Proxy).

The requested resource has been temporarily relocated to another address. Specify this address in Location (code 307 Temporary Redirect).

The request could not be understood by the server due to malformed syntax (code 400 Bad Request).

A password is required to access the document or the user must be registered (code 401 Unauthorized).

Internal error or server configuration error (code 402 Payment Required).

The access to the document is forbidden (code403 Forbidden). To have the page indexed, allow access to it.

The document doesn't exist (code 404 Not Found). If you deleted a section of the site, you can use robots.txt to prevent the robot from accessing it. If such a page on the site never existed, ignore this error, perhaps someone put an incorrect link to your site.

The method defined in the request (Request-Line) can't be applied for the specified resource, so the robot couldn't index it (code 405 Method Not Allowed).

The required document exists, but the format is incorrect (the language or encoding is not supported by the robot). Code 406 Not Acceptable.

The proxy server requires registration (code 407 Proxy Authentication Required).

The site failed to complete the request within the specified time and the robot disconnected (code 408 Request Timeout).

The request conflicts with another request or with the server configuration (code 409 Conflict).

The requested resource was permanently deleted from the site (code 410 Gone).

The server refuses to accept the request without a certain Content-Length header (code 411 Length Required). Correct the headers on your server. The robot will be able to index the page next time.

The server found a mismatch in one or more request header fields (a failure or an error in the precondition processing). Code 412 Precondition Failed.

The server refuses to process the request because it is larger than the server can handle (code 413 Request Entity Too Large).

The server refuses to process the request, because the URI (Request-URI) requested by the robot is longer than the server can render (code 414 Request-URI Too Long).

The server refuses to process the request, because the request body has an unsupported format (code 415 Unsupported Media Type).

The server refuses to process the request, because the Range field in the request header contains an invalid byte range (code 416 Requested Range Not Satisfiable).

The server refuses to process the request, because the value of the Expect field in the request header is unexpected (code 417 Expectation Failed).

The server can't process one (or more) request element (code 422 Unprocessable Entity).

The server refuses to process the request, because one of the required resources is blocked (code 423 Locked).

The server refuses to process the request, because one of the dependent resources is blocked (code 424 Failed Dependency).

The server requested connection upgrade to SSL, but the client doesn't support SSL (code 426 Upgrade Required).

The server encountered an unexpected condition that doesn't allow it to complete the request (code 500 Internal Server Error).

The server doesn't support the functionality required to execute the request (code 501 Not Implemented). This response means the server doesn't recognize the request method and can't provide it for any resource.

The server acting as a gateway or proxy server received an invalid response from an inbound server it accessed while attempting to fulfill the request (code 502 Bad Gateway).

An error occurred due to temporary overload or disconnection for server maintenance (code 503 Service Unavailable).

The server, while acting as a gateway or proxy, did not receive a timely response from an upstream server it needed to access in order to complete the request (code 504 Gateway Timeout).

The server doesn't support or refuses to support the version of the HTTP protocol used in the robot request message (code 505 HTTP Version Not Supported).

The server can't process the request due to the lack of the disk space (code 507 Insufficient Storage).

The server can't process the request because the requested extension is not supported (code 510 Not Extended).