John Mueller, a Google Webmaster Trends Analyst, stated in an office hours hangout this week that subdomains and subdirectories are treated the same in Google search.
A question came up about whether or not there was a difference between using a subdomain, like example.google.com, versus a subdirectory, like google.com/example.
Mueller gave a fairly succinct and straightforward answer, saying Google treats both of them the same.
He acknowledged that there are strong opinions on either side but, the way he sees it, related content should be grouped together on the same site as much as possible.
For site owners who are trying to decide between using subdomains or subdirectories, Mueller recommends only using a subdomain when it has something different to offer compared to the rest of the site.
If you’re a site owner who doesn’t really care one way or the other, then go ahead and keep everything on the same site using subdirectories.
Mueller’s full response can be heard in the video below, starting at the 11:18 mark.
”In general, we see these the same. I would personally try to keep things together as much as possible. So if it’s the same site then try to put them on the same site, essentially, and use subdomains where things are things are really kind of slightly different.
There are lots of really strong opinions on this so, from my point of view, this is something that could go either way. If you have really strong reasons to go one way or the other then, obviously, that might be what you’d want to watch out for. On the other hand, if you’re like “well I don’t care either way” then I would just keep it within the same site.”