The server has received the request headers and the client should proceed to send the request body

The server is switching protocols as requested by the client via the Upgrade header

The server has received and is processing the request, but no response is available yet (WebDAV)

Used to return some response headers before the final HTTP message, allowing preloading of resources

The request has succeeded. The meaning depends on the HTTP method used

The request has been fulfilled and a new resource has been created

The request has been accepted for processing, but processing has not been completed

The returned metadata is from a local or third-party copy, not the origin server

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

The server successfully processed the request and asks the client to reset the document view

The server is delivering only part of the resource due to a range header sent by the client

A Multi-Status response conveys information about multiple resources (WebDAV)

Members of a DAV binding have already been enumerated and are not included again (WebDAV)

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

The request has more than one possible response and the user or user agent should choose one

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

The URI of the requested resource has been changed temporarily. The client should use the same method for future requests

The response can be found under a different URI and should be retrieved using a GET method

The resource has not been modified since the version specified by the request headers (If-Modified-Since or If-None-Match)

The requested resource must be accessed through the proxy given by the Location field (deprecated)

The request should be repeated with another URI but future requests should still use the original URI. Method and body are not changed

The request and all future requests should be repeated using another URI. Method and body are not changed

The server cannot process the request due to something perceived as a client error (e.g., malformed syntax)

The request requires user authentication. The response must include a WWW-Authenticate header

Reserved for future use. Originally intended for digital payment schemes

The server understood the request but refuses to authorize it. Authentication will not help

The server cannot find the requested resource. The URL is not recognized

The request method is known by the server but is not supported by the target resource

The server cannot produce a response matching the list of acceptable values defined in the request headers

The client must first authenticate itself with the proxy

The server timed out waiting for the request. The client may repeat the request without modifications

The request could not be processed because of conflict in the current state of the resource

The resource requested is no longer available and will not be available again. Unlike 404, this is permanent

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

The server does not meet one of the preconditions specified in the request headers

The request entity is larger than limits defined by the server

The URI provided was too long for the server to process

The media format of the requested data is not supported by the server

The range specified by the Range header cannot be fulfilled

The expectation indicated by the Expect request header cannot be met by the server

The server refuses to brew coffee because it is, permanently, a teapot (RFC 2324, April Fools)

The request was directed at a server that is not able to produce a response

The request was well-formed but could not be followed due to semantic errors (WebDAV)

The resource that is being accessed is locked (WebDAV)

The request failed because it depended on another request that failed (WebDAV)

The server is unwilling to process a request that might be replayed (TLS early data)

The server refuses to perform the request using the current protocol but might after the client upgrades

The origin server requires the request to be conditional to prevent lost updates

The user has sent too many requests in a given amount of time (rate limiting)

The server is unwilling to process the request because its header fields are too large

The user agent requested a resource that cannot legally be provided (censorship, court order)

The server has encountered a situation it doesn't know how to handle

The request method is not supported by the server and cannot be handled

The server received an invalid response from the upstream server while acting as a gateway or proxy

The server is not ready to handle the request, often due to maintenance or overloading

The server is acting as a gateway and did not get a response from the upstream server in time

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

The server has an internal configuration error: transparent content negotiation results in a circular reference

The server is unable to store the representation needed to complete the request (WebDAV)

The server detected an infinite loop while processing the request (WebDAV)

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

The client needs to authenticate to gain network access (e.g., captive portal)