HTTP Status Codes

Every status code you are likely to meet, what it means and where to look next. Codes with a Guide link have a page of their own with the usual causes, the fixes and an example response.

Status codes

49 of 49

Code	Name	Meaning	Guide
100	Continue	The server got the headers; the client can send the body.
101	Switching Protocols	The connection switches protocol, usually to WebSocket.
103	Early Hints	Preload hints sent ahead of the final response.
200	OK	The request succeeded.
201	Created	A resource was created; its URL is in the Location header.
202	Accepted	Accepted for processing that has not finished yet.
204	No Content	Success, with no body to return.
206	Partial Content	Part of the resource, answering a Range request.
301	Moved Permanently	The resource has a new permanent URL.	Guide to 301 Moved Permanently
302	Found	Temporary redirect; clients may turn a POST into a GET.
303	See Other	Fetch the result from another URL, with GET.
304	Not Modified	The cached copy is still valid; no body is sent.	Guide to 304 Not Modified
307	Temporary Redirect	Temporary redirect that keeps the method and body.
308	Permanent Redirect	Permanent redirect that keeps the method and body.
400	Bad Request	The server cannot parse or accept the request.	Guide to 400 Bad Request
401	Unauthorized	Credentials are missing or invalid.	Guide to 401 Unauthorized
402	Payment Required	Reserved; some APIs use it for billing limits.
403	Forbidden	The server understood the request and refuses it.	Guide to 403 Forbidden
404	Not Found	Nothing at this URL, or the server will not say.	Guide to 404 Not Found
405	Method Not Allowed	The URL exists, but not for this HTTP method.	Guide to 405 Method Not Allowed
406	Not Acceptable	Nothing matches the Accept headers the client sent.
407	Proxy Authentication Required	A proxy between client and server wants credentials.
408	Request Timeout	The client took too long to send the request.
409	Conflict	The request clashes with the current state of the resource.	Guide to 409 Conflict
410	Gone	Removed on purpose, with no forwarding address.
411	Length Required	The server needs a Content-Length header.
412	Precondition Failed	An If-Match or If-Unmodified-Since check failed.
413	Content Too Large	The request body is over the server's size limit.	Guide to 413 Content Too Large
414	URI Too Long	The URL, usually its query string, is too long.
415	Unsupported Media Type	The server does not accept the body's Content-Type.
416	Range Not Satisfiable	The requested byte range is outside the file.
417	Expectation Failed	The server cannot meet the Expect header.
418	I'm a teapot	An April Fools' joke from RFC 2324, kept reserved since.
421	Misdirected Request	The connection reached a server that cannot answer for this host.
422	Unprocessable Content	Well-formed, but the data fails validation.	Guide to 422 Unprocessable Content
425	Too Early	The server will not process a request that might be replayed.
426	Upgrade Required	Switch to the protocol named in the Upgrade header.
428	Precondition Required	The server requires a conditional request, such as If-Match.
429	Too Many Requests	Rate limit reached; wait before trying again.	Guide to 429 Too Many Requests
431	Request Header Fields Too Large	The headers, often the cookies, are too large.
451	Unavailable For Legal Reasons	Blocked for legal reasons.
500	Internal Server Error	An unexpected error on the server.	Guide to 500 Internal Server Error
501	Not Implemented	The server does not support this method at all.
502	Bad Gateway	A proxy got an invalid response from the server behind it.	Guide to 502 Bad Gateway
503	Service Unavailable	The server is overloaded or down for maintenance.	Guide to 503 Service Unavailable
504	Gateway Timeout	A proxy gave up waiting for the server behind it.	Guide to 504 Gateway Timeout
505	HTTP Version Not Supported	The server refuses this version of HTTP.
507	Insufficient Storage	The server cannot store what the request needs.
511	Network Authentication Required	A captive portal wants you to log in first.

The five classes

1xx Informational: The request was received and is still being processed.
2xx Success: The request was received, understood and accepted.
3xx Redirection: The client has to do something more, usually follow a redirect.
4xx Client error: Something in the request is wrong or not allowed right now; most need a change before a retry.
5xx Server error: The server failed to handle a request that looks valid.

Commonly confused

401 or 403? Not logged in, or logged in but not allowed.
400 or 422? Can't parse it, or parsed and invalid.
502 or 504? A broken answer, or no answer in time.
429 or 503? Your quota, or the server's capacity.
301 or 308? Both permanent; only 308 keeps a POST a POST.
404 or 410? Not here, or removed for good.