HTTP Status Codes Reference

The server received the request headers; the client may continue sending the body (reply to Expect: 100-continue).

The server agrees to switch protocols as requested in the Upgrade header, e.g. to WebSocket.

WebDAV: the server is still processing a long request; no response yet.

Sent before the final response so the browser can start preloading resources listed in Link headers.

Resumable uploads draft: the server supports resuming interrupted uploads.

The request succeeded. The body contains the requested resource or the result of the action.

A new resource was created; its URL is usually given in the Location header.

The request was accepted for processing, which has not finished yet (asynchronous jobs).

Success, but the returned content was modified by a transforming proxy.

Success with no response body, typical for DELETE or saving data.

Success; the client should reset the form or view that sent the request.

Only part of the resource is returned, as requested with a Range header (resumable downloads, video seeking).

WebDAV: the body contains separate status codes for several resources.

WebDAV: members of a binding were already listed earlier in this response.

Delta encoding: the response is the result of instance manipulations applied to the resource.

Several representations are available and the client may choose one.

The resource has moved permanently to the URL in Location; search engines transfer ranking. Clients may switch POST to GET.

The resource is temporarily at another URL; keep using the original URL. Clients may switch POST to GET.

See another URL with GET, typically after a form POST (Post/Redirect/Get pattern).

The cached copy is still valid (conditional request with If-None-Match / If-Modified-Since); no body is sent.

Deprecated: the resource had to be accessed through a proxy. Not used for security reasons.

Reserved; was used in an earlier draft and is no longer used.

Temporary redirect that keeps the method and body (a POST stays a POST).

Permanent redirect that keeps the method and body (a POST stays a POST).

The server cannot process the request because it is malformed (bad syntax, invalid parameters, invalid JSON).

Authentication is required or failed; the response includes a WWW-Authenticate header.

Reserved for future use; some APIs use it for payment or quota problems.

The server understood the request but refuses it; logging in again will not help.

No resource exists at this URL (or the server does not want to reveal it).

The HTTP method is not supported for this resource; the Allow header lists valid methods.

No representation matches the Accept headers sent by the client.

Like 401, but authentication with the proxy is required.

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

The request conflicts with the current state of the resource (e.g. edit conflict, duplicate).

The resource was removed permanently and will not come back; stronger than 404.

The server requires a Content-Length header.

A precondition such as If-Match or If-Unmodified-Since was not met (optimistic locking).

The request body is larger than the server accepts (upload size limit).

The URL is longer than the server can process.

The body’s media type (Content-Type) is not supported.

The requested Range cannot be satisfied, e.g. it starts beyond the end of the file.

The expectation in the Expect header cannot be met.

Reserved and unused; known from the "I’m a teapot" April Fools’ RFC 2324.

The request reached a server that cannot answer for this host (e.g. reused HTTP/2 connection).

The syntax is correct but the content is semantically invalid (validation errors).

WebDAV: the resource is locked.

WebDAV: the request failed because an action it depended on failed.

The server refuses to process a request that might be replayed (TLS 1.3 early data).

The client must switch to another protocol listed in the Upgrade header.

The server requires a conditional request (If-Match) to prevent lost updates.

Too many requests in a given time (rate limiting); Retry-After says when to try again.

The request headers (or one header, e.g. cookies) are too large.

The resource is unavailable for legal reasons, such as a court order or censorship.

A generic, unexpected error on the server.

The server does not support the functionality required (e.g. an unknown method).

A gateway or proxy received an invalid response from the upstream server.

The server is temporarily overloaded or down for maintenance; Retry-After may be sent.

A gateway or proxy did not get a response from the upstream server in time.

The HTTP version used in the request is not supported.

Content negotiation is misconfigured: the chosen variant itself negotiates.

WebDAV: the server does not have enough storage to complete the request.

WebDAV: the server detected an infinite loop while processing the request.

Obsoleted: further extensions to the request were required (HTTP Extension Framework).

The client must authenticate to gain network access, e.g. a Wi-Fi captive portal.