Liens

1xx Informational Status Codes

Code	Value	Description
200	OK	return of a successful GET or POST call
201	Created	return of a successful POST call to create a resource
204	No Content	return of a successful PUT or DELETE call

Codes	Titres	Explications
301	Moved Permanently
302	Found	The requested resource resides temporarily in another location, but it can still be found at the requested URI.
304	Not Modified	If the client has performed a conditional GET request and access is allowed, but the document has not been modified, the server should respond with this status code.

Code	Value	Description
400	Bad Request	invalid path variables or body
401	Unauthorized	invalid credentials
403	Forbidden	unauthorized access. Unlike 401, the client's identity is known to the server.
404	Not Found	the resource identified in the query (url or body) is not found
422	Unprocessable Entity	The request was well-formed but was unable to be followed due to semantic errors. (ex: invalid data)

Code	Value	Description
500	Internal server error	unexpected error: uncatched exception
502	Bad Gateway	error while calling upstream services
503	Service Unavailable	temporarily unable to handle the request: overload due to high traffic or resource limitations

Code	Value	Description
444	No Response	Used in Nginx logs to indicate that the server has returned no information to the client and closed the connection (useful as a deterrent for malware).
494	Request Header Too Large	Nginx internal code similar to 431 (Request Header Fields Too Large) but it was introduced earlier.
495	Cert Error	Nginx internal code used when SSL client certificate error occurred to distinguish it from 4XX in a log and an error page redirection.
496	No Cert	Nginx internal code used when client didn't provide certificate to distinguish it from 4XX in a log and an error page redirection.
497	HTTP to HTTPS	Nginx internal code used for the plain HTTP requests that are sent to HTTPS port to distinguish it from 4XX in a log and an error page redirection.
499	Client Closed Request	Used in Nginx logs to indicate when the connection has been closed by client while the server is still processing its request, making server unable to send a status code back.
502	Bad Gateway	Le service Fast CGI (pour PHP, ASP ou autres) n'est pas lancé.