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IANA · RFC 9110

HTTP Status Codes

Every HTTP response begins with a three-digit status code. This ledger lists the complete IANA registry — informational, success, redirection, client-error and server-error classes — each with its official name, the RFC that defines it, and a plain-English explanation of what it actually means in practice.

N° 62 / 62
CodeNameWhat it meansReference
1×× Informational
ContinueThe server received the request headers; the client should proceed to send the body.RFC9110
Switching ProtocolsThe server agrees to switch protocols as requested via the Upgrade header.RFC9110
ProcessingThe server has received the request and is processing it, but no response is available yet (WebDAV).RFC2518
Early HintsPreliminary hints (e.g. Link headers) sent before the final response so the browser can preload assets.RFC8297
Upload Resumption Supported (TEMPORARY - registered 2024-11-13, extension registered 2025-09-15, expires 2026-11-13)draft-ietf-httpbis-resumable-upload-05
2×× Success
OKThe request succeeded. The standard response for successful HTTP requests.RFC9110
CreatedThe request succeeded and a new resource was created, typically after POST or PUT.RFC9110
AcceptedThe request was accepted for processing, but processing has not been completed.RFC9110
Non-Authoritative InformationThe response was modified by a transforming proxy from the origin server's 200 response.RFC9110
No ContentThe request succeeded but there is no content to return.RFC9110
Reset ContentThe request succeeded; the client should reset the document view (e.g. clear a form).RFC9110
Partial ContentThe server is delivering only part of the resource due to a Range header (used for downloads and streaming).RFC9110
Multi-StatusMultiple status values for multiple independent operations (WebDAV).RFC4918
Already ReportedMembers of a DAV binding were already enumerated earlier in the response (WebDAV).RFC5842
IM UsedThe server fulfilled a GET request using instance manipulations (delta encoding).RFC3229
3×× Redirection
Multiple ChoicesMultiple options for the resource exist; the client may choose one.RFC9110
Moved PermanentlyThe resource has moved permanently to a new URL. Browsers and search engines update their references.RFC9110
FoundThe resource temporarily resides at a different URL. The original URL should keep being used.RFC9110
See OtherThe response is available at a different URL and should be fetched with GET (typical after form POSTs).RFC9110
Not ModifiedThe cached version is still valid; the resource has not been modified since the last request.RFC9110
Use ProxyDeprecated. The resource must be accessed through a proxy.RFC9110
Temporary RedirectTemporary redirect that preserves the request method and body.RFC9110
Permanent RedirectPermanent redirect that preserves the request method and body.RFC9110
4×× Client Error
Bad RequestThe server cannot process the request due to a client error such as malformed syntax.RFC9110
UnauthorizedAuthentication is required and has failed or has not been provided.RFC9110
Payment RequiredReserved for future use; occasionally used by payment-related APIs.RFC9110
ForbiddenThe server understood the request but refuses to authorize it.RFC9110
Not FoundThe requested resource could not be found on the server. The most famous status code of all.RFC9110
Method Not AllowedThe HTTP method used is not allowed for this resource.RFC9110
Not AcceptableNo content matching the request's Accept headers is available.RFC9110
Proxy Authentication RequiredAuthentication with an intermediate proxy is required first.RFC9110
Request TimeoutThe server timed out waiting for the request.RFC9110
ConflictThe request conflicts with the current state of the resource (e.g. an edit conflict).RFC9110
GoneThe resource is permanently gone and no forwarding address is known.RFC9110
Length RequiredA Content-Length header is required and was not provided.RFC9110
Precondition FailedA precondition in the request headers (If-Match etc.) evaluated to false.RFC9110
Content Too LargeThe request body is larger than the server is willing to process.RFC9110
URI Too LongThe request URI is longer than the server is willing to interpret.RFC9110
Unsupported Media TypeThe media type of the request body is not supported.RFC9110
Range Not SatisfiableThe requested byte range cannot be satisfied.RFC9110
Expectation FailedThe expectation in the Expect header could not be met.RFC9110
Misdirected RequestThe request was directed at a server unable to produce a response (e.g. wrong TLS SNI).RFC9110
Unprocessable ContentThe request is well-formed but semantically invalid and cannot be processed.RFC9110
LockedThe resource is locked (WebDAV).RFC4918
Failed DependencyThe request failed because a previous dependent request failed (WebDAV).RFC4918
Too EarlyThe server is unwilling to process a request that might be replayed (early TLS data).RFC8470
Upgrade RequiredThe client must upgrade to a different protocol to continue.RFC9110
Precondition RequiredThe server requires the request to be conditional to prevent lost updates.RFC6585
Too Many RequestsThe client has sent too many requests in a given time — rate limiting.RFC6585
Request Header Fields Too LargeRequest header fields are too large for the server to process.RFC6585
Unavailable For Legal ReasonsThe resource is unavailable for legal reasons (censorship, court orders, GDPR blocks).RFC7725
5×× Server Error
Internal Server ErrorA generic server-side error; something went wrong and no more specific message applies.RFC9110
Not ImplementedThe server does not support the functionality required to fulfil the request.RFC9110
Bad GatewayA gateway or proxy received an invalid response from the upstream server.RFC9110
Service UnavailableThe server is temporarily unavailable — overloaded or down for maintenance.RFC9110
Gateway TimeoutA gateway or proxy did not receive a timely response from the upstream server.RFC9110
HTTP Version Not SupportedThe HTTP protocol version used in the request is not supported.RFC9110
Variant Also NegotiatesThe server has a circular content-negotiation configuration error.RFC2295
Insufficient StorageThe server has insufficient storage to complete the request (WebDAV).RFC4918
Loop DetectedThe server detected an infinite loop while processing the request (WebDAV).RFC5842
Not Extended (OBSOLETED)Further extensions to the request are required for the server to fulfil it.RFC2774][Status change of HTTP experiments to Historic
Network Authentication RequiredNetwork authentication is required — typically a captive portal (hotel/airport Wi-Fi).RFC6585