Recently, I had both a client and a close friend ask me whether subdomains or subdirectories (aka subfolders) are better for SEO. Ugh. This debate has been going on forever.

You know what I wanted? I wanted a recent, definitive article I could point them to that laid it all out, once and for all.

Instead, I sent them to this confounding Twitter thread below. As if that would explain it all.

TL;DR

Google has stated on the record that there is no SEO benefit to hosting content on subdirectories vs. subdomains, as they can index either one with no problem.

While true, the above statement omits a critical point: subdomains are basically viewed as separate websites.  

Maybe Google doesn’t “favor” one over the other, but they’re still separate. Since subdomains are viewed as separate websites, it follows that consolidating closely related content across a single domain benefits organic relevance more than fracturing equity across two different ones.

In my past 14+ years of doing SEO, I’ve consistently seen increased traffic when content from a subdomain is moved to a subfolder.

Are there exceptions to this rule? Sure. Are there reasons why you might want to host on a subdomain anyway? Absolutely. Please see below for a more complete breakdown, and thanks for reading.

A lot of the controversy around this subject can be traced back to semantics and minutiae. (Two of my favorite things. Not.)

There’s also the added issue that only Googlers will ever be fully privy to the secrets of their own algorithm (or will they?). In the meantime, SEOs are doing the best we can to analyze the patterns that we see, while also never quite agreeing on anything.

So here we are.

In an attempt to clear things up (wish me luck hah), I’ve created a Q&A that dives into the nitty gritty behind this great debate.

Q. Does Google have harder time indexing subdomains?

LOL, no. Google has absolutely zero problem with subdomains. None. It’s all good, okay?

Please see the webmaster hangout below where John Mueller goes into this more. (Yes, the same hangout that everyone was arguing about on Twitter.)

Q. But, does Google still somehow view subdomains as less powerful?

A. Not really. Again, see above video.

Q. Um… Sarah? Why would you tell me that subdirectories are better if Google just said there’s no difference?

A. Google never said that subdomains aren’t different than subdirectories. Instead, Google just said they can easily index either one.

Subdomains are seen as separate websites.

SEPARATE WEBSITES.

Nothing you put on a subdomain is really going to be “part” of your main domain. Subdomains need to be verified separately in Google Search Console, and default settings in Google Analytics will also track performance separately. (Unless you configure subdomain tracking.)

Q. Right. What I meant to say is that Google literally just said there’s no difference in SEO benefit between the two. Correct?

A. Correct. My understanding is that Google isn’t going to look at subdomain and say, “Oooh, let’s assign an SEO penalty (or benefit) to this because it’s on a subdomain!”

Q. OMG. Then why are you writing an entire post about why subdirectories are more powerful?

A. I’m not writing a post about why subdirectories are more powerful.

I’m writing a post about the fact that because subdomains are seen as separate websites, it’s possible that they may not accrue as much content and link equity as if you were to consolidate the same content on a single domain and its subdirectories.

Maybe it would help if we tried a simple quiz. Which website has the most traffic potential?

1. Website.com
   50 pages of fab content and 25 high-quality incoming links.
2. Blog.website.com
   100 pages of fab content and 50 high-quality incoming links
3. Website.com + website.com/blog
   150 pages of fab content and 75 high-quality incoming links

I’m sure you’ve guessed the answer. It’s not about subdomains vs. subdirectories, but about consolidating content on a single domain.

More quality content + more quality links = more positioning power.

Q. Why doesn’t Google talk about how consolidating content on a single domain can often be more effective?

A. Can you imagine if Google suddenly stated that placing content on a subdirectory could be more advantageous?

Webmasters across the world with subdomains would start freaking out. Things would get taken completely out of context, and I bet the “subdomain penalty” would be born. (Similar to the “duplicate content” penalty, as if Google would actually penalize you for having canonicalization problems on your website.)

People would start expecting traffic to improve if they transferred content from a subdomain to a subdirectory. (This is not guaranteed.)  They might also move things around without 301-ing content, or implement crazy DNS schemes that end up causing more harm than good.  And of course, just because you put a bunch more content on your website doesn’t mean anything will happen. It also needs to be excellent content, and that takes sweat plus creativity.

Q. When would you need to host content on a subdomain instead of a subdirectory?

A. Sometimes, it’s just not feasible from a DNS and web server management standpoint to host content on a subdirectory – especially if your content is hosted in two different places.

Hubspot is an interesting example of this. Their customer support team somewhat mirrors Google’s diplomatic stance (grrr) by noting that while subdomains are the only option with their hosted platform, it’s still better than not creating that additional content at all.

Subdomains can also make sense when the content and user experience deserve to be seen as a digital destination in their own right. For example, what if you wanted to add a forum to your website? It might make more sense to place it on a subdomain, because the design and content would have a totally different experience and purpose than your main site.