Status Codes
100 – 199 = information status200 – 299 = success status300 – 399 = redirection status
You will most likely not see the Status Code messages because they are usually not displayed by your browser (client), They often signify the status of interaction between the client and the server,
Error Codes
On the other hand, you’ve got HTTP Error Codes which often signifies a n issue on the client-side, server-side or the gateway between both. They an easily be identified from the three digit designation.
400 – 499 = Client Error500 – 599 = Server Error
This is the side of the coin we will be dealing with and it entails the range of issues emanating from different points in the connection process.
HTTP Error 404 – Not Found
Usually accompanied by page not found, the client side error message simply means that the URL you typed is incorrect or the page you want to visit is no longer there or have been moved without providing a new directory. In this case, the connection between the client and server is successful but nothing was found in the URL provided on the web server.
HTTP Error 400 – Bad Request
It is similar to what we have above being that the connection between server and client was successful. However, the error occurs as result of the inability of the web server to process your request. In other words, the URL does not make any sense to the server so it cannot do anything with it so it send back an Error indicating that the Request is bad.
HTTP Error 401 – Unauthorized
Just like the message says, it means that the page you’re trying to enter requires that you be an admin with a valid username and password to login to the server. You might also get this if your login details are not correct.
HTTP Error 408 – Request Timeout
This error message is seen when the client fails to completely send its request before the server times out. Servers have a time frame within which a request must be submitted and if it doesn’t get it at the end of the said time, an Error 408 is displayed. This might result from heavy traffic on the client or extremely slow internet.
Internal Server Error – Error 500
In line with what was mentioned earlier, this is a server error and the most generic one which is often displayed when the issue is from the server. The message is not specific only indicates that the server is unable to process your valid request due to some technical issue of some sort.
Service unavailable – Error 503
Due to scheduled ongoing maintenance, you might encounter this message or because of a server overload occurring at that moment. This is usually a temporary situation and it eventually gets fixed after a short period of time.
Bad Gateway – Error 502
This is a situation where the configuration on the server side is in conflict with one another causing unsuccessful handshakes between the component therein. The issue is a conflict in protocol on the web server needed for file exchange which then sends a bad gateway error to the client. Most of the issues here are temporary and some are just as a result of a mistake on your own end. It comes in handy to know when you can do something about an occurring error message. However, when the issue emanates from the web server there is often noting you can do besides checking back later.
