List of HTTP status codes - AbsoluteAstronomy.com

The following is a list of HyperText Transfer Protocol
Hypertext Transfer Protocol
The Hypertext Transfer Protocol is a networking protocol for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web....

(HTTP) response status codes. This includes codes from IETF internet standard

Internet standard

In computer network engineering, an Internet Standard is a normative specification of a technology or methodology applicable to the Internet. Internet Standards are created and published by the Internet Engineering Task Force .-Overview:...

s as well as unstandardised RFCs

Request for Comments

In computer network engineering, a Request for Comments is a memorandum published by the Internet Engineering Task Force describing methods, behaviors, research, or innovations applicable to the working of the Internet and Internet-connected systems.Through the Internet Society, engineers and...

, other specifications and some additional commonly used codes. The first digit of the status code specifies one of five classes of response; the bare minimum for an HTTP client is that it recognises these five classes. Microsoft IIS

Internet Information Services

Internet Information Services – formerly called Internet Information Server – is a web server application and set of feature extension modules created by Microsoft for use with Microsoft Windows. It is the most used web server after Apache HTTP Server. IIS 7.5 supports HTTP, HTTPS,...

may use additional decimal sub-codes to provide more specific information, but these are not listed here. The phrases used are the standard examples, but any human-readable alternative can be provided. Unless otherwise stated, the status code is part of the HTTP/1.1 standard.

1xx Informational

Request received, continuing process.

This class of status code indicates a provisional response, consisting only of the Status-Line and optional headers, and is terminated by an empty line. Since HTTP/1.0 did not define any 1xx status codes, servers must not send a 1xx response to an HTTP/1.0 client except under experimental conditions.

100 Continue

This means that the server has received the request headers, and that the client should proceed to send the request body (in the case of a request for which a body needs to be sent; for example, a POST

POST (HTTP)

In computing, POST is one of many request methods supported by the HTTP protocol used by the World Wide Web. The POST request method is used when the client needs to send data to the server as part of the request, such as when uploading a file or submitting a completed form.In contrast to the GET...

request). If the request body is large, sending it to a server when a request has already been rejected based upon inappropriate headers is inefficient. To have a server check if the request could be accepted based on the request's headers alone, a client must send Expect: 100-continue as a header in its initial request and check if a 100 Continue status code is received in response before continuing (or receive 417 Expectation Failed and not continue).

101 Switching Protocols

This means the requester has asked the server to switch protocols and the server is acknowledging that it will do so.

102 Processing (WebDAV

WebDAV

Web-based Distributed Authoring and Versioning is a set of methods based on the Hypertext Transfer Protocol that facilitates collaboration between users in editing and managing documents and files stored on World Wide Web servers...

) (RFC 2518)

As a WebDAV request may contain many sub-requests involving file operations, it may take a long time to complete the request. This code indicates that the server has received and is processing the request, but no response is available yet. This prevents the client from timing out and assuming the request was lost.

103 Checkpoint

This code is used in the Resumable HTTP Requests Proposal to resume aborted PUT or POST requests.

122 Request-URI too long

This is a non-standard IE7-only code which means the URI is longer than a maximum of 2083 characters. (See code 414.)

2xx Success

This class of status codes indicates the action requested by the client was received, understood, accepted and processed successfully.

200 OK

Standard response for successful HTTP requests. The actual response will depend on the request method used. In a GET request, the response will contain an entity corresponding to the requested resource. In a POST request the response will contain an entity describing or containing the result of the action.

201 Created

The request has been fulfilled and resulted in a new resource being created.

202 Accepted

The request has been accepted for processing, but the processing has not been completed. The request might or might not eventually be acted upon, as it might be disallowed when processing actually takes place.

203 Non-Authoritative Information (since HTTP/1.1)

The server successfully processed the request, but is returning information that may be from another source.

204 No Content

The server successfully processed the request, but is not returning any content.

205 Reset Content

The server successfully processed the request, but is not returning any content. Unlike a 204 response, this response requires that the requester reset the document view.

206 Partial Content

The server is delivering only part of the resource due to a range header sent by the client. The range header is used by tools like wget

Wget

GNU Wget is a computer program that retrieves content from web servers, and is part of the GNU Project. Its name is derived from World Wide Web and get...

to enable resuming of interrupted downloads, or split a download into multiple simultaneous streams.

207 Multi-Status (WebDAV) (RFC 4918)

The message body that follows is an XML

XML

Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....

message and can contain a number of separate response codes, depending on how many sub-requests were made.

208 Already Reported (WebDAV) (RFC 5842)

The members of a DAV binding have already been enumerated in a previous reply to this request, and are not being included again.

226 IM Used (RFC 3229)

The server has fulfilled a GET request for the resource, and the response is a representation of the result of one or more instance-manipulations applied to the current instance.

3xx Redirection

The client must take additional action to complete the request.

This class of status code indicates that further action needs to be taken by the user agent in order to fulfil the request. The action required may be carried out by the user agent without interaction with the user if and only if the method used in the second request is GET or HEAD. A user agent should not automatically redirect a request more than five times, since such redirections usually indicate an infinite loop

Infinite loop

An infinite loop is a sequence of instructions in a computer program which loops endlessly, either due to the loop having no terminating condition, having one that can never be met, or one that causes the loop to start over...

.

300 Multiple Choices

Indicates multiple options for the resource that the client may follow. It, for instance, could be used to present different format options for video, list files with different extensions, or word sense disambiguation

Word sense disambiguation

In computational linguistics, word-sense disambiguation is an open problem of natural language processing, which governs the process of identifying which sense of a word is used in a sentence, when the word has multiple meanings...

301 Moved Permanently

HTTP 301

The HTTP response status code 301 Moved Permanently is used for permanent redirection. This status code should be used with the location header...

This and all future requests should be directed to the given URI

Úri

Úriis a village and commune in the comitatus of Pest in Hungary....

302 Found

HTTP 302

The HTTP response status code 302 Found is the most common way of performing a redirection.It is an example of industry practice contradicting the standard HTTP/1.0 specification , which required the client to perform a temporary redirect , but popular browsers implemented it as a 303 See Other , i.e...

This is an example of industrial practice contradicting the standard. HTTP/1.0 specification (RFC 1945) required the client to perform a temporary redirect (the original describing phrase was "Moved Temporarily"), but popular browsers implemented 302 with the functionality of a 303 See Other. Therefore, HTTP/1.1 added status codes 303 and 307 to distinguish between the two behaviours. However, some Web applications and frameworks use the 302 status code as if it were the 303.

303 See Other

HTTP 303

The HTTP response status code 303 See Other is the correct manner in which to redirect web applications to a new URI, particularly after an HTTP POST has been performed....

(since HTTP/1.1)

The response to the request can be found under another URI

Uniform Resource Identifier

In computing, a uniform resource identifier is a string of characters used to identify a name or a resource on the Internet. Such identification enables interaction with representations of the resource over a network using specific protocols...

using a GET method. When received in response to a POST (or PUT/DELETE), it should be assumed that the server has received the data and the redirect should be issued with a separate GET message.

304 Not Modified

Indicates the resource has not been modified since last requested. Typically, the HTTP client provides a header like the If-Modified-Since header to provide a time against which to compare. Using this saves bandwidth and reprocessing on both the server and client, as only the header data must be sent and received in comparison to the entirety of the page being re-processed by the server, then sent again using more bandwidth of the server and client.

305 Use Proxy (since HTTP/1.1)

Many HTTP clients (such as Mozilla

Mozilla

Mozilla is a term used in a number of ways in relation to the Mozilla.org project and the Mozilla Foundation, their defunct commercial predecessor Netscape Communications Corporation, and their related application software....

and Internet Explorer

Internet Explorer

Windows Internet Explorer is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems, starting in 1995. It was first released as part of the add-on package Plus! for Windows 95 that year...

) do not correctly handle responses with this status code, primarily for security reasons.

306 Switch Proxy

No longer used. Originally meant "Subsequent requests should use the specified proxy."

307 Temporary Redirect (since HTTP/1.1)

In this occasion, the request should be repeated with another URI, but future requests can still use the original URI. In contrast to 303, the request method should not be changed when reissuing the original request. For instance, a POST request must be repeated using another POST request.

308 Resume Incomplete

This code is used in the Resumable HTTP Requests Proposal to resume aborted PUT or POST requests.

4xx Client Error

The 4xx class of status code is intended for cases in which the client seems to have erred. Except when responding to a HEAD request, the server should include an entity containing an explanation of the error situation, and whether it is a temporary or permanent condition. These status codes are applicable to any request method. User agents should display any included entity to the user.

400 Bad Request

The request cannot be fulfilled due to bad syntax.

401 Unauthorized

Similar to 403 Forbidden, but specifically for use when authentication is possible but has failed or not yet been provided. The response must include a WWW-Authenticate header field containing a challenge applicable to the requested resource. See Basic access authentication and Digest access authentication

Digest access authentication

Digest access authentication is one of the agreed upon methods a web server can use to negotiate credentials with a user's web browser. It uses encryption to send the password over the network which is safer than the Basic access authentication that sends plaintext.Technically digest...

402 Payment Required

Reserved for future use. The original intention was that this code might be used as part of some form of digital cash or micropayment

Micropayment

A micropayment is a financial transaction involving a very small sum of money and usually one that occurs online. PayPal defines a micropayment as a transaction of less than 12 USD while Visa prefers transactions under 20 Australian dollars, and though micropayments were originally envisioned to...

scheme, but that has not happened, and this code is not usually used. As an example of its use, however, Apple's MobileMe

MobileMe

MobileMe was a subscription-based collection of online services and software offered by Apple Inc. Originally launched on January 5, 2000, as iTools, a free collection of Internet-based services for users of Mac OS 9, Apple relaunched it as .Mac on July 17, 2002, when it became a paid subscription...

service generates a 402 error ("httpStatusCode:402" in the Mac OS X Console log) if the MobileMe account is delinquent.

403 Forbidden

HTTP 403

In the HTTP protocol used on the World Wide Web, 403 Forbidden is an HTTP status code returned by a web server when a user requests a web page or media that the server does not allow them to. In other words, the server can be reached, but the server declined to allow access to the page. This...

The request was a legal request, but the server is refusing to respond to it. Unlike a 401 Unauthorized response, authenticating will make no difference.

404 Not Found

HTTP 404

The 404 or Not Found error message is a HTTP standard response code indicating that the client was able to communicate with the server, but the server could not find what was requested. A 404 error should not be confused with "server not found" or similar errors, in which a connection to the...

The requested resource could not be found but may be available again in the future. Subsequent requests by the client are permissible.

405 Method Not Allowed

A request was made of a resource using a request method not supported by that resource; for example, using GET on a form which requires data to be presented via POST, or using PUT on a read-only resource.

406 Not Acceptable

The requested resource is only capable of generating content not acceptable according to the Accept headers sent in the request.

407 Proxy Authentication Required

The client must first authenticate itself with the proxy.

408 Request Timeout

The server timed out waiting for the request. According to W3 HTTP specifications: "The client did not produce a request within the time that the server was prepared to wait. The client MAY repeat the request without modifications at any later time."

409 Conflict

Indicates that the request could not be processed because of conflict in the request, such as an edit conflict

Edit conflict

An edit conflict is a computer software problem encountered on wikis. An edit conflict occurs when a shared document is being edited by more than one person at the same time and a conflict is generated...

410 Gone

Indicates that the resource requested is no longer available and will not be available again. This should be used when a resource has been intentionally removed and the resource should be purged. Upon receiving a 410 status code, the client should not request the resource again in the future. Clients such as search engines should remove the resource from their indices. Most use cases do not require clients and search engines to purge the resource, and a "404 Not Found" may be used instead.

411 Length Required

The request did not specify the length of its content, which is required by the requested resource.

412 Precondition Failed

The server does not meet one of the preconditions that the requester put on the request.

413 Request Entity Too Large

The request is larger than the server is willing or able to process.

414 Request-URI Too Long

The URI

Úri

Úriis a village and commune in the comitatus of Pest in Hungary....

provided was too long for the server to process.

415 Unsupported Media Type

The request entity has a media type

Internet media type

An Internet media type, originally called a MIME type after MIME and sometimes a Content-type after the name of a header in several protocols whose value is such a type, is a two-part identifier for file formats on the Internet.The identifiers were originally defined in RFC 2046 for use in email...

which the server or resource does not support. For example, the client uploads an image as image/svg+xml

Scalable Vector Graphics

Scalable Vector Graphics is a family of specifications of an XML-based file format for describing two-dimensional vector graphics, both static and dynamic . The SVG specification is an open standard that has been under development by the World Wide Web Consortium since 1999.SVG images and their...

, but the server requires that images use a different format.

416 Requested Range Not Satisfiable

The client has asked for a portion of the file, but the server cannot supply that portion. For example, if the client asked for a part of the file that lies beyond the end of the file.

417 Expectation Failed

The server cannot meet the requirements of the Expect request-header field.

418 I'm a teapot (RFC 2324)

This code was defined in 1998 as one of the traditional IETF April Fools' jokes

April Fools' Day RFC

Almost every April Fools' Day since 1989, the Internet Engineering Task Force has published one or more humorous RFC documents, following in the path blazed by the June 1973 RFC 527 entitled ARPAWOCKY, which parodied Lewis Carroll's nonsense poem Jabberwocky...

, in RFC 2324, Hyper Text Coffee Pot Control Protocol
Hyper Text Coffee Pot Control Protocol
The Hyper Text Coffee Pot Control Protocol is a protocol for controlling, monitoring, and diagnosing coffee pots.HTCPCP is specified in the jocular RFC 2324, published on 1 April 1998. Although the RFC describing the protocol is an April Fools' Day joke, it specifies the protocol accurately enough...

, and is not expected to be implemented by actual HTTP servers. However, known implementations do exist.

422 Unprocessable Entity (WebDAV) (RFC 4918)

The request was well-formed but was unable to be followed due to semantic errors.

423 Locked (WebDAV) (RFC 4918)

The resource that is being accessed is locked.

424 Failed Dependency (WebDAV) (RFC 4918)

The request failed due to failure of a previous request (e.g. a PROPPATCH).

425 Unordered Collection (RFC 3648)

Defined in drafts of "WebDAV Advanced Collections Protocol", but not present in "Web Distributed Authoring and Versioning (WebDAV) Ordered Collections Protocol".

426 Upgrade Required (RFC 2817)

The client should switch to a different protocol such as TLS/1.0

Transport Layer Security

Transport Layer Security and its predecessor, Secure Sockets Layer , are cryptographic protocols that provide communication security over the Internet...

428 Precondition Required

The origin server requires the request to be conditional. Intended to prevent "the 'lost update' problem, where a client GETs a resource's state, modifies it, and PUTs it back to the server, when meanwhile a third party has modified the state on the server, leading to a conflict." Proposed in an Internet-Draft.

429 Too Many Requests

The user has sent too many requests in a given amount of time. Intended for use with rate limiting

Rate limiting

In computer networks, rate limiting is used to control the rate of traffic sent or received on a network interface. Traffic that is less than or equal to the specified rate is sent, whereas traffic that exceeds the rate is dropped or delayed...

schemes. Proposed in an Internet-Draft.

431 Request Header Fields Too Large

The server is unwilling to process the request because either an individual header field, or all the header fields collectively, are too large. Proposed in an Internet-Draft.

444 No Response

An nginx

Nginx

nginx is a Web server and a reverse proxy server for HTTP, SMTP, POP3 and IMAP protocols, with a strong focus on high concurrency, performance and low memory usage. It is licensed under a BSD-like license and it runs on Unix, Linux, BSD variants, Mac OS X, Solaris, and Microsoft Windows.- Overview...

HTTP server extension. The server returns no information to the client and closes the connection (useful as a deterrent for malware).

449 Retry With

A Microsoft extension. The request should be retried after performing the appropriate action.

450 Blocked by Windows Parental Controls

A Microsoft extension. This error is given when Windows Parental Controls are turned on and are blocking access to the given webpage.

499 Client Closed Request

An Nginx HTTP server extension. This code is introduced to log the case when the connection is closed by client while HTTP server is processing its request, making server unable to send the HTTP header back.

5xx Server Error

The server failed to fulfill an apparently valid request.

Response status codes beginning with the digit "5" indicate cases in which the server is aware that it has encountered an error or is otherwise incapable of performing the request. Except when responding to a HEAD request, the server should include an entity containing an explanation of the error situation, and indicate whether it is a temporary or permanent condition. Likewise, user agents should display any included entity to the user. These response codes are applicable to any request method.

500 Internal Server Error

A generic error message, given when no more specific message is suitable.

501 Not Implemented

The server either does not recognise the request method, or it lacks the ability to fulfill the request.

502 Bad Gateway

The server was acting as a gateway or proxy and received an invalid response from the upstream server.

503 Service Unavailable

The server is currently unavailable (because it is overloaded or down for maintenance). Generally, this is a temporary state.

504 Gateway Timeout

The server was acting as a gateway or proxy and did not receive a timely response from the upstream server.

505 HTTP Version Not Supported

The server does not support the HTTP protocol version used in the request.

506 Variant Also Negotiates (RFC 2295)

Transparent content negotiation

Content negotiation

Content negotiation is a mechanism defined in the HTTP specification that makes it possible to serve different versions of a document at the same URI, so that user agents can specify which version fit their capabilities the best...

for the request results in a circular reference

Circular reference

A circular reference is a series of references where the last object references the first, resulting in a closed loop.-In language:A circular reference is not to be confused with the logical fallacy of a circular argument...

507 Insufficient Storage (WebDAV) (RFC 4918)

The server is unable to store the representation needed to complete the request.

508 Loop Detected (WebDAV) (RFC 5842)

The server detected an infinite loop while processing the request (sent in lieu of 208).

509 Bandwidth Limit Exceeded (Apache bw/limited extension)

This status code, while used by many servers, is not specified in any RFCs.

510 Not Extended (RFC 2774)

Further extensions to the request are required for the server to fulfill it.

511 Network Authentication Required

The client needs to authenticate to gain network access. Intended for use by intercepting proxies used to control access to the network (e.g. "captive portals" used to require agreement to Terms of Service before granting full Internet access via a Wi-Fi hotspot). Proposed in an Internet-Draft.

598 (Informal convention) network read timeout error

This status code is not specified in any RFCs, but is used by some HTTP proxies to signal a network read timeout behind the proxy to a client in front of the proxy.

599 (Informal convention) network connect timeout error

This status code is not specified in any RFCs, but is used by some HTTP proxies to signal a network connect timeout behind the proxy to a client in front of the proxy.

External links

IANA: Hypertext Transfer Protocol (HTTP) Status Code Registry
Microsoft Knowledge Base: MSKB943891: The HTTP status codes in IIS 7.0
Google Help: HTTP status codes
Help for HTTP errors
Test any HTTP status code in a web browser
Adobe Flash status code definitions (e.g. 408)