The 5 Main types of HTTP status codes and What they mean

I’m sure everyone has at some point clicked on a link from a website and gotten the infamous error 404 page not found. But did you know that 404 is merely one of many different types of codes that are formally called  HTTP status codes? While the code 404 is indicative of an error, not all HTTP status codes like that. Some are indicative of success and others have different meanings. Let’s dive into what these five types are about.

HTTP Status Codes

1.   1XX

Status codes that start with 100, indicate that the request sent by the client was received by the server and the server is going to continue processing the request. What this means is that the server is telling the client which may be a browser to relax as it has received the request for information.

2.   2XX

If the status code starts with 200, then everything has gone splendidly well as this category of code tells you that the server not only has received the request but it has also understood it, accepted it, and completed processing the request. Essentially this is the best status update you can hope for.

3.   3XX

This series of status codes are meant mainly for links that have been moved, and thus when the server returns this status code it also passes on the new address along with it. Then the client, which in most cases will be your web browser will go to the new link that was provided. This is useful as it avoids 404 page not found errors.

4.   4XX

This category is for errors that have been caused by the client’s side. The most famous of these codes is the error you get when you try to open a dead link. The server will give you the renown “Error 404, Page Not Found” message. What this means is that the user agent requested something that the server cannot fulfill.

5.   5XX

Now the 500 series of status codes is also indicative of an error, but unlike those that start with 400 it is not being caused by the client. This error instead is being caused by the server itself. As in something has gone wrong from the server’s side that it has failed to complete the request made by the client. Essentially the server is saying my bad, I cannot perform the action you want.

Above is a simplified explanation of what each category of status codes generally means. Each category has plenty of codes that go into more specific detail. Did you know there are almost 30 error codes that start with the number 400? Click here to find a detailed breakdown of all the 5 different categories of HTTP status codes.