Subdomain vs. Subfolder for SEO?

Google Web Search is fine with using either subdomains or subdirectories. Making changes to a site’s URL structure tends to take a bit of time to settle down in Search. So I recommend picking a setup that you can keep for longer. Some servers make it easier to set up different parts of a website as subdirectories. That’s fine for us. This helps us with crawling since we understand that everything’s on the same server and can crawl it in a similar way. Sometimes this also makes it easier for users who recognize that these sections are all a part of the same bigger website. On other servers, using subdirectories for different sections, like a blog in a shop, can be trickier, and it’s easier to put them on separate subdomains. That also works for us. You’ll need to verify subdomains separately in Search Console, make any changes to settings, and track overall performance per subdomain. We do have to learn how to crawl them separately, but for the most part, that’s just a formality for the first few days. So in short, use what works best for your setup and think about your longer-term plans when picking one or the other.

They are roughly equivalent. I would basically go with whichever one is easier for you in terms of configuration, your CMSs, all that sort of stuff. So let’s use mattcutts.com as an example. I have mattcutts.com/blog because it was just easier to put stuff in a subdirectory. I don’t have to have a DNS subdomain. I don’t have to worry about moving it around. If I move domains, I don’t have to worry about losing that subdomain. But it might be easier for some people to do a subdomain. Or maybe you want to have your blog powered by some completely different product, WordPress VIP or Tumblr or whatever, and so you want to have that on a separate CNAME. And that’s totally fine as well. The historical context is, we used to crowd by what we would call host, where a host is basically a subdomain, and we would only allow two results from each host. And in that situation, it might make sense to have more subdomains because you could get two results from one host name, and then two results from another subdomain, and just repeat that. And what we did is, we saw that people would abuse that. And they would make a whole bunch of subdomains that they could get more and more results on the page. And so we changed our scoring such that now we’re more likely to squnch those together. That’s the technical term, to squnch them together. So in order to ensure diversity, we say, OK, well the first two, three results, that might make more sense. But maybe it’s a little harder for that third, or fourth, or fifth result to show up from a given domain. Not just from a subdomain. So the historical reasons why you might have wanted to go for a subdomain don’t really apply as much. And that leaves you with, OK, both are on the same domain over all, and so it’s really a question of which one is easier for you. Whichever one makes you happier, I’d go ahead and do it that way.