HTTP status codes reference

    Codes 3xx (redirection)

    A list of HTTP status codes used for request redirection (codes 3xx).

    Code Error Description
    300 Multiple choice

    The requested URL points to more than one resource, and the robot could not determine which page the URL refers to (code 300 Multiple Choices is received).

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

    301 Resource moved permanently

    The server does not use this document any more, and the link redirects to another page (code 301 Moved Permanently is received).

    As the users will not be able to see such documents, displaying them in search results makes no sense, and the robot does not index them. However the robot will surely index the page to which the redirection is set up.

    302 Resource moved temporarily

    The requested resource has been temporarily moved to another address (code 302 Found is received).

    As the users will not be able to see such documents, displaying them in search results makes no sense, and the robot does not index them. However the robot will surely index the page to which the redirection is set up.

    303 See another resource

    The requested resource resides at another address and should be requested using GET method (code 303 See Other) is received). If you want the page in question to appear in the search, it must respond with code 200.

    304 Resource not modified

    304 Not Modified code was returned. If your page has not changed since the last time the robot accessed your site, we recommend returning this code. This will speed up indexing and decrease traffic.

    305 Use proxy

    Access to the requested resource is only possible through the proxy server specified in the Location header (code 305 Use Proxy is received).

    307 Temporary redirection

    The requested resource has been temporarily moved to another address that should be registered in Location (code 307 Temporary Redirect) is received).

    Codes 4xx (client error)

    Contains a list of HTTP status codes that denote possible errors in client request (codes 4xx).

    Code Error Description
    400 Invalid request

    The server cannot understand the request because of incorrect syntax (code 400 Bad Request is received).

    401 Unauthorized request

    To access the document, one must enter a password or be a registered user (code 401 Unauthorized is received).

    402 Payment required for the query

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

    403 Access to resource forbidden

    Access to the document is forbidden (code 403 Forbidden is received). If you want this page to be indexed, allow access to it.

    404 Resource not found

    The document does not exist (code 404 Not Found is received). If you have deleted a certain section of the site, you can disallow the robot to access it, using robots.txt. If such page never existed at your site, please ignore the error. It is possible that someone published an incorrect link to your site.

    405 Method not allowed

    The method specified in the Request-Line is not allowed for this resource, and the robot could not index the resource (code 405 Method Not Allowed is received).

    406 Unacceptable request

    The requested document exists, but in another format (its language or encoding are not supported by the robot). Code 406 Not Acceptable is received.

    407 Firewall, proxy authentication required

    Proxy server authentication is required (code 407 Proxy Authentication Required is received).

    408 Request timeout

    The site did not transfer the complete request during the specified time, and the robot has terminated the connection (code 408 Request Timeout is received).

    409 Conflict

    The request is in conflict with another request or with server configuration (code 409 Conflict is received).

    410 Resource unavailable

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

    411 Length must be specified

    The server rejects requests without a certain header, Content-Length (code 411 Length Required is received). Correct the headers on the server, and then the robot will be able to index the page next time.

    412 Precondition processing failure

    In the course of processing one or more fields of the request header a discrepancy was discovered (a failure or error of precondition processing). Code 412 Precondition Failed is received.

    413 The body of the request is too long.

    The server rejects the request because it is too long for the server to process (code 413 Request Entity Too Large is received).

    414 Unacceptable length of URI request

    The server rejects the request because the URI requested by the robot (Request-URI) is too long for the server to process (code 414 Request-URI Too Long is received).

    415 Unsupported MIME type

    The server rejects the request because the format of the request body is not supported (code 415 Unsupported Media Type is received).

    416 The range cannot be processed

    The server rejects the request because the value of the Range field in the request header specifies an unacceptable range (code 416 Requested Range Not Satisfiable is received).

    417 Expectation failure

    The server rejects the request because the value of the Expect field in the request header does not match expectation (code 417 Expectation Failed is received).

    422 Unprocessable entity

    The server cannot process one or more request elements (code 422 Unprocessable Entity is received).

    423 Locked

    The server rejects the request because one of the requested resources is locked (code 423 Locked is received).

    424 Invalid dependency

    The server rejects the request because one of the requested resources is locked (code 424 Failed Dependency is received).

    426 Upgrade required

    The server requests connection upgrade to SSL, but the client does not support SSL (code 426 Upgrade Required is received).

    Codes 5xx (server error)

    Contains a list of HTTP status codes that denote possible errors in server request (codes 5xx).

    Code Error Description
    500 Internal server error

    The server encountered an unexpected condition that prevents it from fulfilling the request (code 500 Internal Server Error is received).

    501 Method not supported

    The server does not support the features required to fulfill the request (code 501 Not Implemented is received). This response is returned in the situations when the server cannot recognize the request method and cannot provide it for any resource.

    502 Gateway error.

    A server, acting as gateway or proxy, received unacceptable response from the next server in the request chain which it tried to access to fulfill the request (code 502 Bad Gateway is received).

    503 Service unavailable

    An error occurred because of temporary overload or planned maintenance downtime of the server (code 503 Service Unavailable is received).

    504 Gateway timeout

    A server, acting as external gateway or proxy, did not receive response from the next server further up in the request chain which it tried to access to fulfill the request (code 504 Gateway Timeout is received).

    505 HTTP version is not supported

    The server does not support the version of the HTTP protocol used in the robot request message (code 505 HTTP Version Not Supported is received).

    507 Insufficient space

    The server cannot process the request because there is not enough space on disk (code 507 Insufficient Storage is received).

    510 Extensions are missing

    The server cannot process the request because the requested extension is not supported (code 510 Not Extended is received).