One topic that comes up time and time again in the comments on our Multisite posts is SEO.
People often want to know how running a Multisite network will affect SEO, both for the main site and for other sites or blogs in the network.
There isn’t a simple answer to the question “How will Multisite affect my SEO?” The way in which SEO and Multisite interact will depend on how the network is set up, what kind of domains you’re using and how you want your SEO to work. Some network admins want the whole network to be treated as one site for SEO purposes, while others want each site to be treated differently.
In this post, I’ll look at three different scenarios and how they affect SEO – one will help if you want your network to share SEO juice, and the other two will work best if you want each site to be treated differently by search engines.
But let’s start by summarizing the options you have in Multisite.
Multisite and Domains: Your Options
Multisite gives you two options for managing the domains used by the sites in your network:
- Subdirectories: If you set your network up with subdirectories, a site within it will have the domain http://mynetwork.com/mysite, where mynetwork.com is the domain of your network and mysite is the individual site.
- Subdomains: With this setup, your site will have the domain http://mysite.mynetwork.com
You have to specify which of these you’ll use when you activate Multisite, and you can’t change it afterwards. If you’re activating Multisite on an established WordPress installation you can only use subdomains, and if your network isn’t in your domain’s root directory you’ll have to use subdirectories.
However, there is a third option that will override either of these and that’s domain mapping. With the dWordPress MU Domain Mapping plugin you can map a completely separate domain (or multiple domains) to any of the sites in your network, which means that your site can have the domain http://mysite.com and will behave as if it’s hosted on that domain instead of in your network.
Search Engines and Domains
As Google is the search engine most of us worry about, let’s take a look at how Google treats subdomains and subdirectories.
In a Google+ hangout in August 2016, Google’s John Mueller gave us a few clues as to how Google treats subdomains:
“With subdomains, the main thing I’d watch out for is that you’re not using wildcard subdomains because that can make crawling really, really hard. If we have to go through all of these subdomains and treat them all as separate hosts. But if you have a limited number of subdomains then that might be an option. Similarly, if you have different sites that are essentially completely separate websites but they’re in subdirectories … then we’ll try to figure that out as well. And say, well, actually these are … separate sites that should be treated completely separately – then we’ll try to figure that out as well. So that’s not something that would … like improve or hurt rankings. It’s more a matter of us figuring that out. And so far I’ve seen our algorithms do a pretty good job of that.”
You can watch the entire hangout here:
My understanding of this is that Google does its best to work out how your sites should be treated regardless of whether they’re using subdomains or not. Google will treat subdomains as separate hosts if you’re using wildcard subdomains, but if not, it might not if the content is related. And if you’re using subdirectories, then Google will do its best to treat them as separate sites if the content makes it clear that that’s the case.
Which is good news if you already have a Multisite network and can’t change your setup – Google will try to respond to the way your content works and not just the way your domains are set up.
But if you’re setting up a new Multisite network, I’d still advise using the domain approach that will give you the best results for SEO. If you’re managing separate sites with overlaps in their content, or related sites with very different content, then it pays not to rely on Google’s algorithm working it out. After all, it can’t hurt to make life as easy as possible for Google.
So how do each of the three Multisite options interact with SEO?
