HTTP Status Codes

ContinueRFC 9110

Headers received; the client should send the request body.

Switching ProtocolsRFC 9110

Server agrees to switch protocol, e.g. to WebSocket via Upgrade.

ProcessingRFC 2518

WebDAV: request received and still being processed.

Early HintsRFC 8297

Preload hints (Link headers) sent before the final response.

OKRFC 9110

Standard success. Body depends on the method.

CreatedRFC 9110

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

AcceptedRFC 9110

Request accepted for asynchronous processing that hasn't finished.

Non-Authoritative InformationRFC 9110

Payload was modified by a transforming proxy.

No ContentRFC 9110

Success with no body — common for DELETE and PUT.

Reset ContentRFC 9110

Success; the client should reset the document view (e.g. clear a form).

Partial ContentRFC 9110

Only the requested byte range is returned (Range header, video seeking, resumable downloads).

Multi-StatusRFC 4918

WebDAV: body contains multiple status codes for sub-requests.

Already ReportedRFC 5842

WebDAV: members already listed earlier in the response.

IM UsedRFC 3229

Response is the result of instance manipulations (delta encoding).

Multiple ChoicesRFC 9110

Several representations are available; the client should choose.

Moved PermanentlyRFC 9110

Permanent redirect. Search engines transfer ranking. Clients may change POST to GET.

FoundRFC 9110

Temporary redirect. Clients may change POST to GET.

See OtherRFC 9110

Redirect to another URL with GET — typical after a form POST.

Not ModifiedRFC 9110

Cached copy is still valid (If-None-Match / If-Modified-Since). No body.

Temporary RedirectRFC 9110

Temporary redirect that keeps the method and body.

Permanent RedirectRFC 9110

Permanent redirect that keeps the method and body.

Bad RequestRFC 9110

Malformed syntax, invalid framing or failed validation.

UnauthorizedRFC 9110

Authentication is missing or invalid. Should include WWW-Authenticate.

Payment RequiredRFC 9110

Reserved; used by some APIs for billing or quota issues.

ForbiddenRFC 9110

Authenticated but not allowed. Re-authenticating won't help.

Not FoundRFC 9110

No resource at this URL (or the server hides that it exists).

Method Not AllowedRFC 9110

The method isn't supported here. Must include an Allow header.

Not AcceptableRFC 9110

Nothing matches the Accept* headers sent by the client.

Proxy Authentication RequiredRFC 9110

Authenticate with the proxy first.

Request TimeoutRFC 9110

The server gave up waiting for the client to finish the request.

ConflictRFC 9110

Conflicts with the current state — edit conflicts, duplicate keys.

GoneRFC 9110

Permanently removed with no forwarding address. Stronger than 404 for SEO.

Length RequiredRFC 9110

A Content-Length header is required.

Precondition FailedRFC 9110

A conditional header (If-Match, If-Unmodified-Since) didn't match.

Content Too LargeRFC 9110

Request body exceeds the server's limit.

URI Too LongRFC 9110

The URL is longer than the server will process.

Unsupported Media TypeRFC 9110

The Content-Type of the body isn't supported.

Range Not SatisfiableRFC 9110

The requested byte range is outside the resource.

Expectation FailedRFC 9110

The Expect header can't be met.

I'm a teapotRFC 2324

April Fools' joke from HTCPCP; sometimes used to refuse bots.

Misdirected RequestRFC 9110

Sent to a server that can't produce a response for this host (HTTP/2 connection reuse).

Unprocessable ContentRFC 9110

Well-formed but semantically invalid — common for validation errors in APIs.

LockedRFC 4918

WebDAV: the resource is locked.

Failed DependencyRFC 4918

WebDAV: failed because a previous request failed.

Too EarlyRFC 8470

Server won't process a request that might be replayed (TLS early data).

Upgrade RequiredRFC 9110

Client must switch to another protocol (see Upgrade header).

Precondition RequiredRFC 6585

Request must be conditional to avoid lost updates.

Too Many RequestsRFC 6585

Rate limited. Check the Retry-After header.

Request Header Fields Too LargeRFC 6585

Headers (often cookies) are too large.

Unavailable For Legal ReasonsRFC 7725

Blocked for legal reasons, e.g. censorship or a court order.

Client Closed Requestnon-standard

nginx: the client closed the connection before the response.

Internal Server ErrorRFC 9110

Generic server failure — an unhandled exception.

Not ImplementedRFC 9110

The server doesn't support the functionality required.

Bad GatewayRFC 9110

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

Service UnavailableRFC 9110

Overloaded or down for maintenance. May include Retry-After.

Gateway TimeoutRFC 9110

A proxy or gateway didn't get an upstream response in time.

HTTP Version Not SupportedRFC 9110

The HTTP version used isn't supported.

Variant Also NegotiatesRFC 2295

Content negotiation configuration error.

Insufficient StorageRFC 4918

WebDAV: the server can't store the representation.

Loop DetectedRFC 5842

WebDAV: infinite loop detected.

Network Authentication RequiredRFC 6585

Log in to the network first (captive portal).

Web Server Returned an Unknown Errornon-standard

Cloudflare: origin returned an empty or unexpected response.

Web Server Is Downnon-standard

Cloudflare: origin refused the connection.

Connection Timed Outnon-standard

Cloudflare: TCP connection to the origin timed out.

A Timeout Occurrednon-standard

Cloudflare: origin didn't send an HTTP response within 100 s.