http response status codes

created  2025/11/19
category internet
views    32

a response status code indicates whether a specific http(s) request has been successfully completed. they are grouped in five classes:

informational

100 Continue

this interim response indicates that the client should continue the request or ignore the response if the request is already finished

101 Switching Protocols

this code is sent in response to an [Upgrade](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Upgrade) request header from the client and indicates the protocol the server is switching to

102 Processing (deprecated)

this code was used in WebDAV contexts to indicate that a request has been received by the server, but no status was available at the time of the response

103 Early Hints

this status code is primarily intended to be used with the [Link](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Link) header, letting the user agent start [preloading](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes/rel/preload) resources while the server prepares a response or [preconnect](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes/rel/preconnect) to an origin from which the page will need resources

successful

200 OK

the request succeeded. the result and meaning depends on the HTTP method

for `HEAD` representation headers are included in the response without any body

for `TRACE` the message body contains the request as received by the server

201 Created

the request succeeded, and a new resource was created as a result. this is typically the response sent after POST requests, or some PUT requests

202 Accepted

the request has been received but not yet acted upon. it is noncommittal, since there is no way in HTTP to later send an asynchronous response indicating the outcome of the request. it is intended for cases where another process or server handles the request, or for batch processing

203 Non-Authoritative Information

this response code means the returned metadata is not exactly the same as is available from the origin server, but is collected from a local or a third-party copy. this is mostly used for mirrors or backups of another resource. except for that specific case, the [200 OK](#200 OK) response is preferred to this status

204 No Content

there is no content to send for this request, but the headers are useful. the user agent may update its cached headers for this resource with the new ones

205 Reset Content

tells the user agent to reset the document which sent this request

206 Partial Content

this response code is used in response to a [range request](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/Range_requests) when the client has requested a part or parts of a resource

redirection

300 Multiple Choices

in [agent-driven content negotiation](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/Content_negotiation#agent-driven_negotiation), the request has more than one possible response and the user agent or user should choose one of them. there is no standardized way for clients to automatically choose one of the responses, so this is rarely used

301 Moved Permanently

the URL of the requested resource has been changed permanently. the new URL is given in the response

302 Found

this response code means that the URI of requested resource has been changed temporarily. further changes in the URI might be made in the future, so the same URI should be used by the client in future requests

303 See Other

the server sent this response to direct the client to get the requested resource at another URI with a GET request

304 Not Modified

this is used for caching purposes. it tells the client that the response has not been modified, so the client can continue to use the same [cached](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/Caching) version of the response

305 Use Proxy (deprecated)

defined in a previous version of the HTTP specification to indicate that a requested response must be accessed by a proxy. it has been deprecated due to security concerns regarding in-band configuration of a proxy

306 unused

this response code is no longer used; but is reserved. it was used in a previous version of the HTTP/1.1 specification

307 Temporary Redirect

the server sends this response to direct the client to get the requested resource at another URI with the same method that was used in the prior request. this has the same semantics as the [302 Found](#302 Found) response code, with the exception that the user agent must not change the HTTP method used: if a POST was used in the first request, a POST must be used in the redirected request

308 Permanent Redirect

this means that the resource is now permanently located at another URI, specified by the [Location](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Location) response header. this has the same semantics as the [301 Moved Permanently](#301 Moved Permanently) HTTP response code, with the exception that the user agent must not change the HTTP method used: if a POST was used in the first request, a POST must be used in the second request

client error

400 Bad Request

the server cannot or will not process the request due to something that is perceived to be a client error (e.g., malformed request syntax, invalid request message framing, or deceptive request routing)

401 Unauthorized

Although the HTTP standard specifies "unauthorized", semantically this response means "unauthenticated". that is, the client must authenticate itself to get the requested response

402 Payment Required

the initial purpose of this code was for digital payment systems, however this status code is rarely used and no standard convention exists

403 Forbidden

the client does not have access rights to the content; that is, it is unauthorized, so the server is refusing to give the requested resource. unlike [401 Unauthorized](#401 Unauthorized), the client's identity is known to the server

404 Not Found

the server cannot find the requested resource. in the browser, this means the URL is not recognized. in an API, this can also mean that the endpoint is valid but the resource itself does not exist. servers may also send this response instead of [403 Forbidden](#403 Forbidden) to hide the existence of a resource from an unauthorized client. this response code is probably the most well known due to its frequent occurrence on the web

405 Method Not Allowed

the [request method](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Methods) is known by the server but is not supported by the target resource. for example, an API may not allow DELETE on a resource, or the TRACE method entirely

406 Not Acceptable

this response is sent when the web server, after performing [server-driven content negotiation](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/Content_negotiation#server-driven_content_negotiation), doesn't find any content that conforms to the criteria given by the user agent

407 Proxy Authentication Required

this is similar to [401 Unauthorized](#401 Unauthorized) but authentication is needed to be done by a proxy

408 Request Timeout

this response is sent on an idle connection by some servers, even without any previous request by the client. it means that the server would like to shut down this unused connection. this response is used much more since some browsers use HTTP pre-connection mechanisms to speed up browsing. some servers may shut down a connection without sending this message

409 Conflict

this response is sent when a request conflicts with the current state of the server. in WebDAV remote web authoring, `409` responses are errors sent to the client so that a user might be able to resolve a conflict and resubmit the request

410 Gone

this response is sent when the requested content has been permanently deleted from server, with no forwarding address. clients are expected to remove their caches and links to the resource. the HTTP specification intends this status code to be used for "limited-time, promotional services". APIs should not feel compelled to indicate resources that have been deleted with this status code

411 Length Required

server rejected the request because the [Content-Length](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Content-Length) header field is not defined and the server requires it

412 Precondition Failed

in conditional requests, the client has indicated preconditions in its headers which the server does not meet

413 Content Too Large

the request body is larger than limits defined by server. the server might close the connection or return a [Retry-After](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Retry-After) header field

414 URI Too Long

the URI requested by the client is longer than the server is willing to interpret

415 Unsupported Media Type

the media format of the requested data is not supported by the server, so the server is rejecting the request

416 Range Not Satisfiable

the [ranges](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/Range_requests) specified by the [Range](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Range) header field in the request cannot be fulfilled. it's possible that the range is outside the size of the target resource's data

417 Expectation Failed

this response code means the expectation indicated by the [Expect](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Expect) request header field cannot be met by the server

418 I'm a teapot

the server refuses the attempt to brew coffee with a teapot

421 Misdirected Request

the request was directed at a server that is not able to produce a response. this can be sent by a server that is not configured to produce responses for the combination of scheme and authority that are included in the request URI

422 Unprocessable Content (WebDAV)

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

423 Locked (WebDAV)

the resource that is being accessed is locked

424 Failed Dependency (WebDAV)

the request failed due to failure of a previous request

425 Too Early Experimental

indicates that the server is unwilling to risk processing a request that might be replayed

426 Upgrade Required

the server refuses to perform the request using the current protocol but might be willing to do so after the client upgrades to a different protocol. the server sends an [Upgrade](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Upgrade) header in a `426` response to indicate the required protocol(s)

428 Precondition Required

the origin server requires the request to be [conditional](https://developer.mozilla.org/en-US/docs/Web/HTTP/Guides/Conditional_requests). this response is 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

429 Too Many Requests

the user has sent too many requests in a given amount of time. (ratelimiting)

431 Request Header Fields Too Large

the server is unwilling to process the request because its header fields are too large. the request may be resubmitted after reducing the size of the request header fields

451 Unavailable For Legal Reasons

the user agent requested a resource that cannot legally be provided, such as a web page censored by a government

server error

500 Internal Server Error

the server has encountered a situation it does not know how to handle. this error is generic, indicating that the server cannot find a more appropriate `5XX` status code to respond with

501 Not Implemented

the request method is not supported by the server and cannot be handled. the only methods that servers are required to support (and therefore that must not return this code) are GET and HEAD

502 Bad Gateway

this error response means that the server, while working as a gateway to get a response needed to handle the request, got an invalid response

503 Service Unavailable

the server is not ready to handle the request. common causes are a server that is down for maintenance or that is overloaded. note that together with this response, a user-friendly page explaining the problem should be sent. this response should be used for temporary conditions and the [Retry-After](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Retry-After) HTTP header should, if possible, contain the estimated time before the recovery of the service. the webmaster must also take care about the caching-related headers that are sent along with this response, as these temporary condition responses should usually not be cached

504 Gateway Timeout

this error response is given when the server is acting as a gateway and cannot get a response in time

505 HTTP Version Not Supported

the HTTP version used in the request is not supported by the server

506 Variant Also Negotiates

the server has an internal configuration error: during content negotiation, the chosen variant is configured to engage in content negotiation itself, which results in circular references when creating responses

507 Insufficient Storage (WebDAV)

the method could not be performed on the resource because the server is unable to store the representation needed to successfully complete the request

508 Loop Detected (WebDAV)

the server detected an infinite loop while processing the request

510 Not Extended

the client request declares an HTTP Extension ([RFC 2774](https://datatracker.ietf.org/doc/html/rfc2774)) that should be used to process the request, but the extension is not supported

511 Network Authentication Required

indicates that the client needs to authenticate to gain network access