HTTP Status Codes Reference

1xx — Informational

Code	Name	Description
100	Continue	The server has received the request headers and the client should proceed to send the request body.
101	Switching Protocols	The server is switching protocols as requested by the client (e.g., upgrading to WebSocket).
102	Processing	The server has received and is processing the request, but no response is available yet (WebDAV).
103	Early Hints	Used to return some response headers before the final response, allowing the client to preload resources.

2xx — Success

Code	Name	Description
200	OK	The request succeeded. The meaning depends on the HTTP method used.
201	Created	The request succeeded and a new resource was created as a result.
202	Accepted	The request has been received but not yet acted upon. It is intended for asynchronous processing.
203	Non-Authoritative Information	The returned metadata is from a local or third-party copy, not the origin server.
204	No Content	The request succeeded but there is no content to return in the response body.
205	Reset Content	The server asks the client to reset the document view (e.g., clear a form).
206	Partial Content	The server is delivering only part of the resource due to a Range header sent by the client.
207	Multi-Status	Conveys information about multiple resources in situations where multiple status codes might be appropriate (WebDAV).

3xx — Redirection

Code	Name	Description
300	Multiple Choices	The request has more than one possible response. The client should choose one.
301	Moved Permanently	The resource has been permanently moved to a new URL. Search engines will update their links.
302	Found	The resource is temporarily located at a different URL. The client should continue using the original URL.
303	See Other	The response can be found at a different URL using a GET request.
304	Not Modified	The resource has not been modified since the last request. The client can use its cached version.
307	Temporary Redirect	The resource is temporarily at a different URL. The request method must not change.
308	Permanent Redirect	The resource has permanently moved. The request method must not change (like 301 but method-preserving).

4xx — Client Error

Code	Name	Description
400	Bad Request	The server cannot process the request due to malformed syntax or invalid parameters.
401	Unauthorized	The request requires authentication. The client must provide valid credentials.
402	Payment Required	Reserved for future use. Some APIs use it to indicate a payment is required.
403	Forbidden	The server understood the request but refuses to authorize it. Authentication will not help.
404	Not Found	The server cannot find the requested resource. The URL may be incorrect or the resource may have been removed.
405	Method Not Allowed	The HTTP method used is not supported for the requested resource.
406	Not Acceptable	The server cannot produce a response matching the Accept headers sent by the client.
407	Proxy Authentication Required	The client must authenticate with a proxy before the request can proceed.
408	Request Timeout	The server timed out waiting for the client to send a complete request.
409	Conflict	The request conflicts with the current state of the resource (e.g., duplicate entry, edit conflict).
410	Gone	The resource is no longer available and has been permanently removed. Unlike 404, this is intentional.
411	Length Required	The server requires a Content-Length header in the request.
412	Precondition Failed	A condition in the request headers (e.g., If-Match) evaluated to false.
413	Content Too Large	The request body exceeds the size limit defined by the server.
414	URI Too Long	The request URL is longer than the server is willing to interpret.
415	Unsupported Media Type	The server does not support the media type of the request body.
416	Range Not Satisfiable	The Range header in the request cannot be fulfilled (e.g., beyond the resource size).
417	Expectation Failed	The server cannot meet the requirements of the Expect header.
418	I'm a Teapot	An April Fools' joke from RFC 2324. The server refuses to brew coffee because it is a teapot.
422	Unprocessable Content	The server understands the request but cannot process the contained instructions (e.g., validation errors).
425	Too Early	The server is unwilling to process a request that might be replayed (TLS early data).
426	Upgrade Required	The server refuses the request using the current protocol and requires the client to upgrade.
428	Precondition Required	The server requires the request to be conditional (e.g., include If-Match header).
429	Too Many Requests	The client has sent too many requests in a given time period (rate limiting).
431	Request Header Fields Too Large	The server refuses the request because the header fields are too large.
451	Unavailable For Legal Reasons	The resource is unavailable due to legal demands (e.g., government censorship, DMCA).

5xx — Server Error

Code	Name	Description
500	Internal Server Error	The server encountered an unexpected condition that prevented it from fulfilling the request.
501	Not Implemented	The server does not support the functionality required to fulfill the request.
502	Bad Gateway	The server, acting as a gateway or proxy, received an invalid response from an upstream server.
503	Service Unavailable	The server is temporarily unable to handle the request due to maintenance or overload.
504	Gateway Timeout	The server, acting as a gateway, did not receive a timely response from the upstream server.
505	HTTP Version Not Supported	The server does not support the HTTP version used in the request.
506	Variant Also Negotiates	The server has a configuration error in transparent content negotiation.
507	Insufficient Storage	The server cannot store the representation needed to complete the request (WebDAV).
508	Loop Detected	The server detected an infinite loop while processing the request (WebDAV).
510	Not Extended	Further extensions to the request are required for the server to fulfill it.
511	Network Authentication Required	The client needs to authenticate to gain network access (e.g., captive portal).