HTTP Status Codes

1xx Informational

100ContinueServer received request headers, client should proceed
101Switching ProtocolsServer switching to protocol requested by client

2xx Success

200OKStandard successful response
201CreatedResource successfully created
204No ContentSuccess with no response body
206Partial ContentPartial resource returned (range request)

3xx Redirection

301Moved PermanentlyResource permanently moved to new URL
302FoundTemporary redirect
304Not ModifiedCached version is still valid
307Temporary RedirectTemporary redirect, method preserved
308Permanent RedirectPermanent redirect, method preserved

4xx Client Error

400Bad RequestMalformed request syntax
401UnauthorizedAuthentication required
403ForbiddenServer refuses to authorize
404Not FoundResource not found
405Method Not AllowedHTTP method not supported
408Request TimeoutServer timed out waiting
409ConflictRequest conflicts with server state
413Payload Too LargeRequest body exceeds limit
422Unprocessable EntityValidation error
429Too Many RequestsRate limit exceeded

5xx Server Error

500Internal Server ErrorGeneric server error
502Bad GatewayInvalid response from upstream
503Service UnavailableServer temporarily unavailable
504Gateway TimeoutUpstream server timed out