HTTP status codes reference

Code

Error

Description

300

Multiple choices

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

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

301

The resource moved permanently

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

Displaying such pages serves no purpose as users can't view these pages so the robot doesn't index them. However, the robot will index the redirect target page, if it's available.

302

Resource moved temporarily

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

Displaying such pages serves no purpose as users can't view these pages so the robot doesn't index them. However, the robot will index the redirect target page, if it's available.

303

See another resource.

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

304

Resource not modified

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.

305

Use proxy

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

307

Temporary redirection

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

308

The resource moved permanently

The document is no longer used by the server, and the link redirects to another page (code 308 Permanent Redirect).

Displaying such pages serves no purpose as users can't view these pages so the robot doesn't index them. However, the robot will index the redirect target page, if it's available.

Code

Error

Description

400

Invalid request/Bad Request

The server can't understand the request due to incorrect syntax.

401

Unauthorized request

A password is required to access the document or the user must be registered.

402

Payment Required

Internal error or a configuration error on the server.

403

Forbidden

Access to the document is forbidden. To have the page indexed, allow access to it.

404

Not Found

The document doesn't exist. If you deleted a section of the website, you can use robots.txt to prevent the robot from accessing it. If such a page on the website never existed, ignore this error. Somebody could put an incorrect link to your website.

405

Invalid method

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

406

Unacceptable request

The document exists, but the format is incorrect (the robot doesn't support the language or encoding).

407

Proxy or firewall identification is required

Registration on the proxy server is required.

408

Request timed out

The website failed to complete the request within the specified time and the robot disconnected.

409

Conflict

The request conflicts with another request or with the server configuration.

410

Resource unavailable/Gone

The requested resource was permanently deleted from the website.

411

Length Required

The server refuses to accept the request without a certain Content-Length header. Correct the headers on your server so that the robot will be able to index the page next time.

412

Precondition Failed

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

413

Request Entity Too Large

The server refuses to process the request because it is larger than the server can handle.

414

Request-URI Too Long

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

415

Unsupported MIME Type

The server refuses to process the request, because the request body has an unsupported format.

416

Requested Range Not Satisfiable

The server refuses to process the request, because the Range field in the request header contains an invalid byte range.

417

Failed while waiting

The server refuses to process the request, because the value of the Expect field in the request header is unexpected.

422

Unprocessable Entity

The server can't process one or more request elements.

423

Locked

The server refuses to process the request, because one of the required resources is blocked.

424

Incorrect dependency

The server refuses to process the request, because one of the dependent resources is blocked.

426

Upgrade required

The server requested connection upgrade to SSL, but the client doesn't support SSL.

429

Too many requests sent

Too many requests sent in a short time. This may indicate, for example, a DDoS-attack attempt. The response can be accompanied by a Retry-After header that indicates after what time the request can be repeated. Yandex doesn't take this header into account.

Code

Error

Description

500

Internal server error

The server encountered an unexpected condition that doesn't allow it to complete the request.

501

Not Implemented

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

502

Gateway error

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.

503

Service unavailable

An error occurred due to temporary overload or disconnection for server maintenance.

504

Gateway timeout

The server, while acting as a gateway or proxy, didn't receive a timely response from an upstream server it needed to access in order to complete the request.

505

Version Not Supported

The server doesn't support or refuses to support the version of the HTTP protocol used in the robot request message.

507

Insufficient space

The server can't process the request due to the lack of the disk space.

510

Not extended

The server can't process the request because the requested extension isn't supported.