The organizational structure of your website can affect your search engine ranking in a significant way. Though John Mueller of Google says that subdomains and subdirectories don’t matter much when considering how Google indexes and ranks your website, there is evidence that one is superior to the other for SEO. Using the right architecture for your site can increase your ranking on Google, leading to increased traffic and visibility.
Subdomains Versus Subfolders
Subdomains and subfolders are two different types of website architecture. You can tell whether a page is a subdomain or a subfolder by looking at the URL. A subdomain has a word before the main page of the website. For example, https://images.google.com. A subfolder has the words in the URL after the main page of the website. For example, https://moz.com/blog. A subdomain hosts all the content of the site on separate servers and with separate content management systems. Subfolders are usually all hosted on the same server and CMS.
Benefits of Subfolders
Google automatically recognizes a subfolder as a part of your main website. The benefits of links, SEO work or other efforts to raise your search rank will work no matter which page of your site it targets if you use subfolders. They’re a good way to keep things coherent and organized without having to do different targeted marketing and SEO for different domains.
Subfolders and SEO
- Since all the content is definitely indexed under a single site, you get SEO benefits from each part of the website. There’s no risk that a subfolder will compete for rankings with your primary site. Every part of the site is boosted by each SEO effort.
- All crawling activity will be directed to one site. Since Google crawls your site when you update content, updating on any part of the site will help freshen the content for all of the site.
Benefits of Subdomains
Subdomains are used to separate different parts of your website into their own discrete domains. Though John Mueller says Google’s crawlers try to determine which sites go together, in many cases they’re recognized as their own sites and don’t benefit from SEO efforts that target your main domain.
The main benefits of subdomains are organization and structure of your site for users. For example, a website that sells a product might have its landing pages, a store, and a blog. Subdomains let you use a different content management system for each type of page. So if you’re using a blogging site for your blog, a third-party sales management site for your seller page and your own CMS for your landing pages, you might need to use subdomains.
Subdomains and SEO
- A subdomain can use a clear keyword or phrase to signal what the site is about very early in the URL. For example, http://contest.test.com is obviously a portal to a contest being run by the main domain. More clarity can help inspire clicks.
- Subdomains can appear as their own results on Google. If you’re trying to move ahead of similar websites, having multiple Google results that link to your subdomains can increase the number of people that click on your rather than a competitor. The amount of traffic each Google search result receives varies wildly depending on its position. So if you occupy positions one, two and three, you’ll be able to increase your traffic.
- Subdomains are also commonly used to separate areas of a site for localization purposes. Versions of a site with a different language often appear on subdomains.
The Impact of Subfolders on SEO
Even though both Matt Cutts and John Mueller say that there’s no difference in how Google ranks sites organized in subfolders versus those organized in subdirectories, SEO experts have found that there’s a significant difference.
When you switch to a subfolder setup, all the links that point to your main site may give your new page a boost too. A subdirectory setup is like starting from scratch in terms of SEO so many prominent SEO experts and blogs stick with subfolder setups.
Subdomains Can Cause Traffic to Drop
Rand Fishkin of Moz found that their rankings for different keywords were much higher when they switched a page on their site from a subdomain to a subdirectory. According to Rand, they tried it three times in two years. The move never offered good enough results to make the change permanent. Ultimately a subdomain setup almost always loses out to a subfolder setup in terms of traffic. That’s why they should only be used when necessary for business purposes.
Fishkin also writes about Timo Reitnauer’s experience with the iwantmyname blog. When Reitnauer moved from a subfolder setup to a subdomain, he experienced a significant drop in traffic. Even five or six months later, the traffic hadn’t recovered. So it’s not a matter of simply waiting for traffic to find the new page. The issue is that content ranked in the subdirectory simply isn’t getting the same benefits as the content linked in the subfolder did. So even though moving the blog to have more options for maintenance and performance seemed like a good idea at the beginning, it impacted their ability to reach people.
Another example of a subfolder setup being better for rankings is Craig Emerson’s experience. He set up a blog in a subdirectory for a site that had already been established for three years. Even though he set up the blog in such a way that he should have been able to rank for his targeted keywords, he couldn’t get in the top 100 in the Google Blog search tool. So Emerson switched his setup to a subfolder setup. Two weeks later, he was ranking at number 57 for one of his targeted keywords.
Why Subfolders and Subdomains are Different
Even though Google’s crawlers are very intelligent, they aren’t perfect. Google may be able to recognize that a subdomain is part of the main domain. If so, they’ll categorize it as such. However, much of the time, the crawlers will index it as a different site and you’ll lose any ranking benefits picked up by your main site.
Ultimately, unless you have a specific reason to use subdomains, go with subdirectories. The main factors that affect your SEO, like quality content that’s fresh and well-targeted are the same no matter which architecture you use. But since using subdirectories can give you a boost, there’s no reason not to take advantage of it.