Você sabe o que significa cada código de status HTTP? Status 500, 404 e 200 são os mais comuns, mas veja agora a lista completa em inglês:
INFORMAÇÃO
100 Client should continue with the request
101 Server is switching protocols
102 Server has received and is processing the request
103 Resume aborted PUT or POST requests
122 URI is longer than a maximum of 2083 characters
SUCESSO
200 Standard response for successful HTTP requests
201 Request has been fulfilled; new resource created
202 Request accepted, processing pending
203 Request processed, information may be from another source
204 Request processed, no content returned
205 Request processed, no content returned, reset document view
206 Partial resource return due to request header
207 XML, can contain multiple separate responses
208 Results previously returned
226 Request fulfilled, response is instance-manipulations
REDIRECIONAMENTO
300 Multiple options for the resource delivered
301 This and all future requests directed to the given URI
302 Temporary response to request found via alternative URI
303 Permanent response to request found via alternative UR
304 Resource has not been modified since last requested
305 Content located elsewhere, retrieve from there
306 Subsequent requests should use the specified proxy
307 Connect again to different URI as provided
308 Resume-able HTTP requests
ERROS
400 Request cannot be fulfilled due to bad syntax
401 Authentication is possible but has failed
402 Payment required, reserved for future use
403 Server refuses to respond to request
404 Requested resource could not be found
405 Request method not supported by that resource
406 Content not acceptable according to the Accept headers
407 Client must first authenticate itself with the proxy
408 Server timed out waiting for the request
409 Request could not be processed because of conflict
410 Resource is no longer available and will not be available again
411 Request did not specify the length of its content
412 Server does not meet request preconditions
413 Request is larger than the server is willing or able to process
414 URI provided was too long for the server to process
415 Server does not support media type
416 Client has asked for unprovidable portion of the file
417 Server cannot meet requirements of Expect requestheader field
418 I’m a teapot
420 Twitter rate limiting
422 Request unable to be followed due to semantic errors
423 Resource that is being accessed is locked
424 Request failed due to failure of a previous request
426 Client should switch to a different protocol
428 Origin Server requires the request to be conditional
429 user has sent too many requests in a given amount of time
431 Server is unwilling to process the request
444 Server returns no information and closes the connection
449 Request should be retried after performing action
450 Windows Parental Controls blocking access to webpage
451 The Server cannot reach the client’s mailbox.
499 Connection closed by client while HTTP server is processing
SERVIDOR
500 Generic error message
501 Server does not recognize method or lacks ability to fulfill
502 Server received an invalid response from upstream serve
503 Server is currently unavailable
504 Gateway did not receive response from upstream server
505 Server does not support the HTTP protocol version
506 Content negotiation for the request results in a circular reference
507 Server is unable to store the representation
508 Server detected an infinite loop while processing the request
509 Bandwidth limit exceeded
510 Further extensions to the request are required
511 Client needs to authenticate to gain network access
598 Network read timeout behind the proxy
599 Network connect timeout behind the proxy
Quer uma mãozinha para ajudar a entender cada tipo de erro ainda mais?
Aqui na nossa mãe Wikipedia você tem alguns traduzidos e explicados em português.
Neste site você também encontra uma funcionalidade bacana de testar cada tipo de status em tempo real
Um grande abraço a todos!