There are sub domains and there are sub directories, which one should you use? In this article, I’m going to explain what sub domains and sub directories are, as well as, breakdown, which ones should you use.

A sub domain is keyword.yourdomain.com

A sub-directory is yourdomain.com/keyword

Think of it this way, if your blog is like mine and it’s on marketing, and you only have marketing related content, all your topics and your categories for your URL structure should be yourdomain .com slash whatever you’re discussing, slash blog, slash about, slash tools.

So, in my case, you would use sub directories. Why? Because everything is around the same topic.

Now, the moment your site is on multiple topics, let’s say, you’re a directory, and you’re a directory that talks about protein, but also travel. You would do protein.yourdomain.com, as well as travel.yourdomain.com.

The reason you want to break it up into sub-domains is because they’re on totally different topics. Think of a sub-domain as a different site. Even though it’s on the same domain name that you’re telling Google and search engines that, hey, this is off topic, so I’m going to create a sub-domain for this section of the site and treat it like a different site.

When I’ve done SEO tests, what I’ve found is, when you’re doing sub domains versus sub directories, roughly 90% of your link juice transfers through a sub-domain. But when you’re doing a sub-directory 100% of your link juice transfers through.

If your site is on multiple topics, you want to use sub domains. Reason being is, Google likes ranking niche websites better than authority sites that talk about everything. That is unless you have a ton and ton of links, like a Wikipedia.

But if you’re talking about bodybuilding, travel, food, even if you have domain authority, you’re not going to rank that high.

The Huffington Posts, the Entrepreneur.com and BBC get away with it because they have so many links, but you’re not going to have that.

To conclude, use sub-domains when you want to do different topics. If you don’t want to do different topics, and you just want to stick to one niche, do sub-directories.

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