A 301 Moved Permanently is an HTTP response status code indicating that the requested resource has been permanently moved to a new URL provided by the Location response header. The 3xx category of response codes are used to indicate redirection messages to the client, such that the client will become… continue reading →

The 401 Unauthorized Error is an HTTP response status code indicating that the request sent by the client could not be authenticated. This is similar yet distinctly different from the 403 Forbidden Error we looked at in a previous article, which indicates that authentication may have been provided by the… continue reading →

A 503 Service Unavailable Error is an HTTP response status code indicating that a server is temporarily unable to handle the request. This may be due to the server being overloaded or down for maintenance. This particular response code differs from a code like the 500 Internal Server Error we… continue reading →

The 400 Bad Request Error is an HTTP response status code that indicates that the server was unable to process the request sent by the client due to invalid syntax. As with the dozens of potential HTTP response codes, receiving a 400 Bad Request Error while accessing your own application… continue reading →

A 504 Gateway Timeout Error is an HTTP response status code indicating that a server, which is currently acting as a gateway or proxy, did not receive a timely response from another server further upstream. As with most HTTP response codes that indicate an error like this, it can be… continue reading →

The 404 Not Found Error is an HTTP response status code, which indicates that the requested resource could not be found. Like most HTTP response codes, and particularly for those codes that indicate an error, the cause of a 404 Not Found Error can be difficult to track down and… continue reading →

The 403 Forbidden Error is an HTTP response status code, which indicates that the identified client does not have proper authorization to access to the requested content. As with most HTTP response codes, particularly those that indicate an error, the appearance of a 403 Forbidden Error can be a challenge… continue reading →

HTTP response codes, particularly those that represent an error, can be difficult to deal with. While some are simple, others have obtuse or confusing meanings and, worst of all, since these codes are the result of a much broader relationship between the client, the web application, a web server, and… continue reading →

People who develop and maintain web applications usually dread a 500 Internal Server Error. This isn’t because these errors are usually hard to fix, however. It’s because the error is usually not specific and can occur for a number of different reasons. The best way to debug the error depends… continue reading →