HTTP Status codes

The web works by the HTTP protocol and each resource is fetched using a request. All requests to a server return a specific status code, which indicates if the request was successful or not. Status codes are divided into the following categories:
  • 1xx: Informational
  • 2xx: Success
  • 3xx: Redirection
  • 4xx: Client Error
  • 5xx: Server Error
This means that just by looking at the first number you can identify what the issue is.   Some of the most popular status codes are displayed in the table below:
Status Code Code Name Explanation
100 Continue Successfully connected and headers received. Server wants other content (like POST data).
200 OK Successfully connected and page is returned.
204 No Content Successfully connected but no page is returned.
300 Multiple Choices There are different pages for the client to follow
301 Moved Permanently The resource has moved to another URI
304 Not Modified Content has not been modified since the last request
307 Temporary Redirect Resource has moved to another location for a temporary period.
400 Bad Request The HTTP request was constructed with wrong syntax
401 Unauthorized Not enough permission to access the resource.
403 Forbidden Not enough permission to access the resource.
404 Not Found Most popular error code. Page not found
405 Method Not Allowed This HTTP request is not allowed
500 Internal Server Error There was an error on the server.
501 Not Implemented Request method not recognized by the server
502 Bad Gateway The server acting as a gateway received an invalid response
503 Service Unavailable The server is currently unavailable
504 Gateway Timeout The server acting as a gateway received a timeout
505 HTTP Version Not Supported The server does not support the HTTP Protocol version.
For more explanation on this topic please refer to the Wikipedia article.  
Related Posts