IANA HTTP Status Code Reference

Search the local IANA HTTP status table by code, English or Traditional Chinese text, with filters for every response class.

http-status-codesLOCAL WORKSPACE

Enabling local controls…

Search code or English / Chinese text (up to 200 characters)

Show daily-use codes only

64 of 64 registrations

IANA HTTP Status Code Registry · Static data date: 2026-10-17

Daily-use is a local selection of 20 codes, not an IANA category. API use cases follow each row's RFC / IANA reference. Usage review date: 2026-10-22

Includes temporary, deprecated and unused registrations; excludes unassigned ranges. Temporary 104 expires 2026-11-13; 418 is currently unused and 510 is obsoleted. A status code does not establish root cause or retry safety.

Code	Registered name	Brief explanation	When to use (API)
100	Continue	Continue sending the request.	Acknowledge Expect: 100-continue before receiving request content. Reference
101	Switching Protocols	The connection changes protocol.	Confirm an agreed protocol switch using Upgrade headers. Reference
102	Processing	Processing continues.	Legacy WebDAV interim processing response; consult the defining extension before use. Reference
103	Early Hints	Preliminary response hints.	Send provisional Link hints while preparing the final response. Reference
104	Upload Resumption Supported (temporary; expires 2026-11-13)	Temporary upload-resumption registration.	Temporary registration for resumable uploads; check current IANA status and the draft protocol. Reference
200	OK	The request succeeded.	Return a successful result using the requested method's response semantics. Reference
201	Created	A resource was created.	Report a newly created resource; identify its URI with Location when applicable. Reference
202	Accepted	Accepted for later processing.	Accept asynchronous work without claiming completion; provide a status monitor when possible. Reference
203	Non-Authoritative Information	An intermediary transformed the response.	A transforming proxy returns modified origin content. Reference
204	No Content	Success without response content.	Confirm success with no response content, such as an update with nothing to return. Reference
205	Reset Content	Reset the input view.	Confirm success and ask the client to reset the document view; send no content. Reference
206	Partial Content	A requested range is returned.	Serve a satisfiable Range request with appropriate Content-Range metadata. Reference
207	Multi-Status	Multiple resource statuses are reported.	Return WebDAV results containing separate statuses for multiple resources. Reference
208	Already Reported	Already included in the report.	Avoid repeating members already reported in a WebDAV binding response. Reference
226	IM Used	Instance manipulation was applied.	Return an instance-manipulation result under negotiated delta encoding. Reference
300	Multiple Choices	Several representations are available.	Offer multiple available representations for the client to select. Reference
301	Moved Permanently	The resource has a permanent location.	Point to a permanent URI; historical clients may change POST to GET. Reference
302	Found	Use another location temporarily.	Point to a temporary URI; historical clients may change POST to GET. Reference
303	See Other	Retrieve a different resource.	Direct the client to retrieve another resource, commonly after POST. Reference
304	Not Modified	The cached representation is unchanged.	Answer a conditional GET/HEAD whose cached representation remains valid; send no content. Reference
305	Use Proxy	Legacy proxy instruction; deprecated.	Deprecated proxy instruction; do not choose it for a new API. Reference
306	Unused	Reserved and unused.	Reserved and unused; do not select it for an API response. Reference
307	Temporary Redirect	Temporary redirect preserving the method.	Redirect temporarily while requiring the method and content to be preserved. Reference
308	Permanent Redirect	Permanent redirect preserving the method.	Redirect permanently while requiring the method and content to be preserved. Reference
400	Bad Request	The request could not be understood.	Reject a client request with malformed syntax, framing or deceptive routing. Reference
401	Unauthorized	Authentication credentials are required.	Challenge missing or invalid credentials with a WWW-Authenticate header. Reference
402	Payment Required	Reserved for payment-related use.	Reserved for future use; define application payment errors explicitly instead of assuming standard semantics. Reference
403	Forbidden	Access was refused.	Refuse an understood request; 404 can conceal a forbidden resource's existence. Reference
404	Not Found	The target resource was not found.	No current representation exists, or the server chooses not to disclose its existence. Reference
405	Method Not Allowed	The target does not allow this method.	Reject a method unsupported by this resource and include the Allow header. Reference
406	Not Acceptable	No acceptable representation is available.	No available representation satisfies proactive content negotiation preferences. Reference
407	Proxy Authentication Required	The proxy requires authentication.	A proxy requests credentials using Proxy-Authenticate. Reference
408	Request Timeout	Receiving the request took too long.	The server did not receive the complete request within its waiting period. Reference
409	Conflict	The current resource state conflicts.	Reject a change that conflicts with the current resource state and explain how to resolve it. Reference
410	Gone	The resource is no longer available.	The resource is unavailable and that condition is likely permanent. Reference
411	Length Required	A content length is required.	Refuse a request that lacks a required Content-Length header. Reference
412	Precondition Failed	A request precondition failed.	A supplied request precondition evaluates to false, such as a stale If-Match. Reference
413	Content Too Large	The request content exceeds the limit.	Reject content larger than the server is willing or able to process. Reference
414	URI Too Long	The request target is too long.	Reject a request target URI longer than the server can interpret. Reference
415	Unsupported Media Type	The content media type is unsupported.	Reject an unsupported request content format or content coding. Reference
416	Range Not Satisfiable	The requested range cannot be served.	The requested byte ranges are unsatisfiable for the selected representation. Reference
417	Expectation Failed	The Expect requirement cannot be met.	The server cannot meet the request's Expect header requirements. Reference
418	Unused	Currently registered as unused.	Currently unused in the HTTP standard registry; do not assign it standard API semantics. Reference
421	Misdirected Request	The request reached an unsuitable server.	Reject a request directed to a server unable to produce an authoritative response. Reference
422	Unprocessable Content	The content instructions cannot be processed.	The content type and syntax are understood, but its instructions cannot be processed. Reference
423	Locked	The resource is locked.	A WebDAV source or destination resource is locked. Reference
424	Failed Dependency	A required operation failed.	A WebDAV operation failed because an action it depended on failed. Reference
425	Too Early	Processing risks an early-data replay.	Decline early-data processing because the request could be replayed. Reference
426	Upgrade Required	A protocol upgrade is required.	Require another protocol and indicate acceptable protocols with Upgrade. Reference
428	Precondition Required	A conditional request is required.	Require a conditional request to help prevent lost updates. Reference
429	Too Many Requests	The request rate exceeds the limit.	Apply a request rate limit; Retry-After may indicate a waiting period, not retry safety. Reference
431	Request Header Fields Too Large	The request headers exceed the limit.	Reject oversized request header fields, individually or in total. Reference
451	Unavailable For Legal Reasons	A legal restriction prevents access.	Explain that access is denied due to a legal demand, when disclosure is permitted. Reference
500	Internal Server Error	The server encountered an unexpected failure.	Report an unexpected server condition that prevented fulfillment. Reference
501	Not Implemented	The server lacks this functionality.	The server does not support functionality required to fulfill the request. Reference
502	Bad Gateway	The upstream response was invalid.	A gateway or proxy received an invalid response from an upstream server. Reference
503	Service Unavailable	The service is temporarily unavailable.	Report temporary overload or maintenance; Retry-After may describe expected duration. Reference
504	Gateway Timeout	The upstream response took too long.	A gateway or proxy timed out waiting for a required upstream response. Reference
505	HTTP Version Not Supported	The HTTP version is unsupported.	The server refuses or does not support the request's major HTTP version. Reference
506	Variant Also Negotiates	Representation negotiation has a configuration loop.	Report a server negotiation configuration error involving a variant resource. Reference
507	Insufficient Storage	The server cannot store the result.	A WebDAV server cannot store the representation needed to complete the request. Reference
508	Loop Detected	A processing loop was detected.	A WebDAV operation detected an infinite loop while processing bindings. Reference
510	Not Extended (Obsoleted)	Obsoleted extension requirement.	Obsoleted extension status; do not choose it for a new API. Reference
511	Network Authentication Required	Network access requires authentication.	An intercepting proxy requires network access authentication, not origin API credentials. Reference

How to use this tool

Browse All or 1xx–5xx, search a code or meaning and consult the linked official registry. The static data date appears with the table.

When not to use it

The table includes temporary, deprecated and unused registrations and excludes unassigned ranges. A code alone does not explain root cause, cache or retry safety.