02What are HTTP Status Codes and Why Do They Affect SEO?

One of the most often overlooked sources of Enterprise SEO headaches is that of HTTP Status Codes. While the codes themselves are very straightforward and easy to understand, many times sites still return the wrong ones. This can give users the impression that your site is not working, or poorly set up. Worse, at least in terms of SEO, it can mean the difference between successfully ranking, or struggling. This is especially true of established sites, where the wrong HTTP Status Codes can also erode authority.

So, what are HTTP Status Codes, and why are they important? Put simply, they’re the information that is exchanged back and forth between the server that hosts your website, and the human or robot that is requesting information. As a general rule, they’re very straightforward and easy to understand, ranging from the 100s through the 500s, with each range of 100 indicating a different set of information. Here’s a quick overview of each number range, and what it means:

100 HTTP Status Codes

These codes are requests for information. Think of it like someone knocking on your door. You need to see who is there, and what they want, before you can proceed to the next step.

200 HTTP Status Codes

These are the success codes. In layman’s terms, it means that the person knocking on the door had pizza, so in they come!

300 HTTP Status Codes

These are redirect codes. A bit like learning that the person at the door has pizza with anchovies, chicken, or other strange toppings that normal SEOs don’t eat. Send it somewhere else.

400 HTTP Status Codes

These are all error codes that indicate the person requesting information has made a mistake. It’s what happens when the pizza guy knocks on the wrong door.

500 HTTP Status Codes

This is what happens when you made a mistake. It occurs when the server is offline, or things just didn’t work out right. Most relationships end this way, and without pizza.

Which Status Codes Affect Your SEO?

Sounds simple, right? Well, it should be, but it isn’t, and here’s why. These codes were in place long before SEO. In fact, they were around before most people even knew what the Internet was. With the growth of the web, and more importantly the focus on user interactions, there have been a lot of changes. Think of it a bit like evolution, only in web terms, there are still quite a few dinosaurs out there. Much like the dreaded T-Rex, they’ll make a meal out of your site’s user experience if you don’t take the proper precautions. Here are the three main ones you’ll want to watch out for:

1. The dreaded 302 Redirect. This monster will redirect users to your new content, but it won’t pass any of the link juice with it. This is because it’s a temporary redirect. While most SEOs know to use a 301 Redirect, because it’s permanent, there are instances where you might end up with an unexpected 302 Redirect. IIS 6 and earlier are prime culprits, as the permanent redirect box is unchecked by default, meaning, any time you don’t check that box, you just got eaten by the 302 Redirect dinosaur. Mmm. Watch out for that one.
2. Return of the dreaded 302 Redirect. Yep, like a bad horror film villain, it’s back. This time, however, it’s because of an application or service side code that defaults to a 302 Redirect. Much like that bad date you were hoping to never bump into again, you won’t even see it until it’s too late. So, keep eyes open, and your wingman of choice nearby, whether it’s analytics from Bing, Google, Yandex, or something else.
3. The 400 Error Codes, worse for Sparta than the 300. This is an area where many SEOs are divided, because while a 404 Error will indicate that a page does not exist, the user might have arrived there through a typo or other error. Other times, a page may have moved, but not been updated. In both cases a standard 404 Error is not a good user experience. Sometimes you’ll want to list that page as a 410 Error, letting search engines and everyone else know that it just isn’t there anymore (I prefer this method). Usually, though, you’re going to want to have either a solid 404 Error page, with a menu and options for the user to navigate elsewhere, or a 301 Redirect.

With all of this in mind, a huge number of sites all over the web suffer from poorly managed HTTP Status Codes. While there are many different reasons the wrong HTTP Status Codes may be on a particular site, your job as an SEO is to fix them.