HTTP status codes

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

The server agrees to change the protocol as requested by the client (e.g., HTTP → WebSocket).

The server is processing the request but does not yet have a response available.

Allows the server to send advance link headers before the final response, optimizing resource load.

The request was successful. The exact meaning depends on the HTTP method used (GET returns the resource, POST returns the result of the action).

The request was successful and a new resource was created. Typically in response to a POST or PUT.

The request was accepted for processing, but the processing has not yet been completed (asynchronous processing).

The request was successful, but the information in the body comes from a third-party cache copy, not the original server.

The request was successful but there is no content to send. Common in responses to successful DELETE or PUT requests.

The request was successful. The client must restart the document view (e.g., clear a form).

The server delivers only part of the resource, as a result of a Range header sent by the client. Used in resumable downloads and streaming.

The response body contains multiple status codes for different sub-resources (WebDAV).

The members of a binding DAV were already listed in a previous response and are not included again (WebDAV).

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

The request has more than one possible answer. The client must choose one of them.

The resource URL has been permanently changed. The new URL is included in the Location header.

The resource is temporarily located at another URI. The client should use the same original URI for future requests.

The server redirects the client to another resource using GET, even though the original request used a different method.

The client cache is up to date. It is used in response to conditional requests (If-None-Match, If-Modified-Since).

The resource must be accessed through a proxy. Obsolete for security reasons.

The resource is temporarily located at another URI. Unlike 302, the HTTP method should not change in the redirect.

The resource permanently moved to another URI. Unlike 301, the HTTP method should not change in the redirect.

The server cannot process the request due to a client error: malformed syntax, invalid parameters, etc.

The client must authenticate itself to obtain the response. The server must include the WWW-Authenticate header.

Reserved for future use. Some services use it to indicate that payment is required.

The client does not have permission to access the resource. Unlike 401, the server knows who the client is but denies access.

The server did not find the requested resource. It is also used to deny access to existing resources without revealing their existence.

The HTTP method used is not allowed for the requested resource. The server must include the Allow header with the allowed methods.

The server cannot produce a response that matches the content negotiation criteria sent by the client.

The client must authenticate with the intermediary proxy before the proxy sends the request to the server.

The server closed the connection because the client took too long to send the complete request.

The request conflicts with the current state of the server (e.g., concurrent modification of the same resource).

The requested resource is no longer available and will not be returned. Unlike 404, it is known for certain that it was removed.

The server rejects the request because the required Content-Length header was not included.

The server evaluated the request's preconditions (If-* headers), and one of them failed.

The request body exceeds the limits defined by the server.

The request URI is longer than the server can interpret.

The request content format is not supported by the server (unsupported MIME type).

The requested byte range cannot be satisfied: it is outside the resource limits.

The server cannot meet the requirements specified in the Expect header of the request.

The server rejects attempts to prepare coffee because it is a teapot. A joke code defined in the RFC of the Hyper Text Coffee Pot Control Protocol (HTCPCP).

The request was sent to a server that cannot produce a response for the combination of scheme and authority.

The request is well-formed but cannot be processed due to semantic errors (e.g., data validation).

The resource you are trying to access is blocked (WebDAV).

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

The server is not willing to process a request that could be repeated, in order to prevent replay attacks.

The server refuses to process the request using the current protocol; the client must upgrade it (e.g., to TLS).

The server requires that the request be conditional (include If-Match headers, etc.) to prevent lost updates.

The client sent too many requests within a given time period (rate limiting).

The server rejects the request because one or more HTTP headers are too long.

The resource is not available for legal reasons (government censorship, court order, etc.).

The server encountered an unexpected condition that prevented it from completing the request. This is the server's generic error code.

The server does not support the functionality required to process the request (e.g., an unrecognized HTTP method).

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

The server is temporarily unavailable, usually due to overload or maintenance. The Retry-After header may indicate when it will be available.

The server, acting as a gateway, did not receive a timely response from the upstream server.

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

Internal configuration error: The selected content variant is configured to negotiate content on its own.

The server cannot store the representation required to complete the request (WebDAV).

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

More extensions are required to the request for the server to process it.

The client must authenticate to access the network (e.g., Wi-Fi captive portal).