Subdomains vs. Subfolders: Expert Cases What Is Better for SEO

In the process of search engine optimization (SEO), you encounter controversial solutions which various web designers or owners of large websites interpret differently. This includes the effectiveness of website subdomains vs subfolders for boosting SEO. By designing a proper website structure, you can effectively promote it in Google search results.

What Is a Subdomain: When to Use a Subdomain

Subfolders and subdomains are two different types of website structure. You can analyze a web page URL to check if it is a subdomain or a subfolder. A subdomain is a keyword before the main website’s domain.

In reality, a subdomain is a separate logical section of a web resource. It functions separately from the main website and almost does not depend on it functionally or subjectively. Oftentimes, large companies use subdomains on their corporate websites. It allows separating content with a distinct topic from the root domain. Let’s take a look at Google and compare websites that belong to the top-level domain google.com. Here are subdomains examples:

1. mail.google.com — Google’s email server.
2. docs.google.com — digital document platform for online editing.
3. drive.google.com — cloud storage service for Google users.

As you can see, these three have similar web addresses that differ by a subdomain and lead to different pages offering different services. Their content is also drastically different. All three subdomains belong to the same owner. Below are the names of each part of the page address you see in your browser.

The main purpose of subdomains is to expand a website or translate it into another language. It is easier and more profitable to create a subdomain than to register a new domain. Note that in most cases the subdomain content is being stored in a separate server location. This may be inconvenient for website administration.

Traffic Drop after Moving to Subdomains and SEO

Do subdomains hurt SEO? There are many examples online when moving a website to subdomain caused it to lose its SEO ranking. Renowned SEO expert Rand Fishkin twitted some links with examples from web designers:

Let’s take a look at Timo Reitnauer’s version of switching iwantmyname.com/blog to a subdomain. Timo says they made this decision after much discussion and research. In their opinion, Google SEO bots should be smart enough so that the website structure would not impact the search results. Matt Cutts, former head of Google webspam, also talked about this.

According to Matt, the only question is what structure a web designer prefers. You should choose the one that is most suitable, and it should not seriously affect website traffic. 

However, sometime after moving to a subdomain, Timo Reitnauer noted there was no positive dynamics in SEO ranking. The number of pageviews dropped the very next month after the move. This trend continued in the following months.

Timo demonstrates a graph of blog page views before and after moving to a subdomain:

As you can see, the pageviews dropped almost by half. Reitnauer clarifies that switching was made by all rules, including 301st redirect for all URLs within the site.

After a while, iwantmyname.com/blog decided to switch back to a subfolder. This decision was heavily influenced by the recommendation of SEO expert Rand Fishkin:

Fishkin says he’s seen dozens of examples of moving to a subdirectory. All of them had a positive effect on search traffic boost, “I would still strongly urge folks to keep all content on a single subdomain”, said Fishkin.

What Subdirectories Are

What is a subfolder or subdirectory? In terms of website structure, subdirectories are more convenient and intuitive to use. A path to a website subfolder within a domain is similar to a path in the file system. Each directory name is separated from the previous one by a forward slash. 

Unlike subdomains, the contents of subdirectories are stored in an individual server partition. One content management system is enough for administrating subfolders.

The infographic below shows the differences between subfolders and subdomains.

 Impactbnd.com

Difference between subdomain and subdirectory— Which is Better for SEO. Are Subdomains Bad for SEO?

To have an adequate website structure, we need to analyze the process of website ranking by SEO bots. Here is what John Mueller, Webmaster & Trends Analyst at Google, says about it.

According to Mueller, the difference between subdomains vs. subfolders is irrelevant for Google’s search algorithms—search bots process them the same way. They use identical ranking factors and algorithms both for subdomains and subfolders. Let’s look at it logically based on the differences in the website structure shown above. 

Since subfolders are a part of the main website, search bots attribute them to the respective domain. In the process of website SEO, this gives us certain advantages when working with external links and developing link weight. For instance, the weight of the link to any main domain page is distributed inside the main website by internal linking. This has a positive effect on SEO promotion.

When choosing a subdomain structure for your website, keep in mind that the weight of external links is distributed only within the individual subdomain. Its promotion will not affect the main domain. This entails separate allocation of additional resources for external links for each website subdomain.

When Subfolders are Preferred

According to many SEO experts, subfolders is the best solution for most websites’ structure. Subdirectories provide a number of significant advantages:

1. Simple and clear logical structure.
2. All webpages and folders are located under a single domain name.
3. Easy website administration.

Moreover, subfolders allow maintaining the weight of external links within one domain name. This is an important factor that determines the website ranking in search results. 

Despite what Google representatives say, Rand Fishkin, Moz co-founder, marketing star and SEO expert himself, also spoke in favor of subfolders in the site structure. To prove that Google’s assertions do not match reality, Fishkin gave the example of the Moz website moving from subdomain to root domain. Also, Fishkin gave a few references to well-known web sources discussing this topic. In his with Rosemary Brisco, technical SEO expert, Rand wrote:

According to Fishkin, Google employees may make any statements but turned out to be wrong in this regard. 

It could be that there’s no specific element that penalized subdomains and maybe they’re viewed the same in Google’s thinking, but there are real ways in which subdomains inherit authority that stays unique to those subdomains and it IS NOT passed between multiple subdomains evenly or equally.’ said Fishkin.

Link Weight within Single Domain

It is known that the weight of external links to a given website page significantly affects its SEO promotion. What is the best option for search engine optimization? Post content on two different subdomains that thousands of websites link to? Or, place all content on one domain with two thousand backlinks? 

For experienced SEOptimizers, the answer to this question is obvious. In the first case, you will need to redouble efforts and financial costs to bring subdomains in the TOP search results. The second option to solve this task two times faster and cheaper. Of course, this example is relative, since the search ranking depends on the quality of incoming links. Let’s assume that the weight of each link is equal in this example. 

This is what Moz co-founder Rand Fishkin is talking about. In such a situation, statements of Google’s representatives make sense. Perhaps SEO bots do not distinguish between subfolders and subdomains. However, dropped link weight on a subdomain is obvious, which has been repeatedly confirmed by web designers and SEO experts. This confirms that SEO bots treat subdomains as individual websites. 

Summing up, website owners should make a final and independent decision regarding the website structure after analyzing website size and promotional budget. Many websites are not large enough to set out separate subdomains unless we are talking about Microsoft, Walt Disney, or other renowned global companies. Subfolders are simpler and easier to understand for an average user. For the website owner, they are more convenient and effective in terms of promotional costs.

Why Use Subdomains

Do not completely abandon the idea of subdomains for your website structure. In some cases, subdomains may be more useful and convenient for the end user. Let’s take a look at an example of a large company that provides various services. In this case, subdomains can be more beneficial and user-friendly. In this approach, you can separate the main company website with basic information about its activities, while attributing description of specific services to subdomains. 

Oftentimes, websites with information for various regions use subdomains. For example, Wikipedia offers materials in different languages. It uses regional subdomains to subdivide content by language. Let’s take a look at the Wikipedia page with an article about the subdomain. It is available in different languages, here are a few:

1. ru.wikipedia.org/wiki/Subdomain — in Russian.
2. en.wikipedia.org/wiki/Subdomain — in English.
3. uk.wikipedia.org/wiki/Subdomain — in Spain.

As you can see, page address belongs to different regional subdomains, such as ru, en, uk. Wikipedia is a world-famous resource and is insanely popular. In this case, the use of subdomains is justified since they do not need additional promotion. A regional subdomain will always be in TOP search results for information requests due to the overall huge popularity of Wikipedia. Achieving such high popularity is extremely difficult, often impossible. You have to be aware of it when choosing to use subdomains.

In the examples above, individual subdomains function as independent websites. Each subdomain has its own audience, own behavioral data, and approaches to its SEO promotion. Each google.com subdomain can be considered as a separate and almost independent business with its own development strategy. Each subdomain brings income to the entire corporation. 

  In addition, the right subdomain keyword or phrase can make the website more recognizable and attract new customers. If you look at support.google.com address, you see right away that it is dedicated to Google customer support. By clicking on it, you can find loads of relevant information and educate yourself about troubleshooting your problem. Thus, you can attract your target audience by using a short and simple subdomain that is easy to recognize. This factor is more psychological than technical. However, it plays an extremely important role in website SEO promotion.

If you were to use subfolders in this case, then the user would have to navigate to the main website and spend time looking for the desired section, and then the web page they are looking for. That is why when using subfolders, special attention should be paid to convenient and clear page design.

To summarize, the decision to use a subdomain may be justified if:

1. All subdomain content is significantly different from the rest of the website content. Storing it on the root domain does not make sense for the website owner and is inconvenient for the user.
2. The subdomain owner has sufficient capabilities to optimize, develop and promote the subdomain. In particular, the subdomain owner will need financial investments to build an external link mass in order to increase the website ranking.
3. There are certain technical limitations that you can’t get around without subdomains.

Remember that when choosing a subdomain it is best to consider it as separate from the root website, as having its own content, own dashboard and own development strategy.

What to Remember When Deciding on Website Structure

As with other contentious SEO issues, there is no exact recipe for deciding on website structure. There is a lot of information and evidence from SEO experts, and Google has an official position on this as well. After having analyzed these facts, you can get a few recommendations for your web designer about when and in which cases it is better to use one or the other option. 

Before you make a final decision, you should clearly answer the questions below. If the answers are mostly positive, consider a subdomain, otherwise, subfolders might work well for your website.

1. Do you have enough financial and technical resources to optimize two or more sites on subdomains equally?
2. Do you have resources to purchase external links to all subdomain sites to boost their SEO rankings by search bots?
3. What kind of content do you plan to place on a subdomain or in a subfolder? If it is very different from the root domain, subdomain might be a more effective option for you. 
4. Do you need a separate content management system or a separate location on your server for data storage?
5. Are you planning to expand your business and translate your website into several languages?

Each website is created for a specific purpose. Naturally, as you optimize and promote your website for SEO, more targeted users visit your website pages. Accordingly, the income of the website owner grows. Based on the foregoing and the promotion strategy used, everyone decides whether to use subfolders or subdomains on their root site. 

Google experts say that there is no difference for SEO bots in ranking subfolders and subdomains. However, real-life examples show otherwise. You can find many examples of moving from a subdomain to a subfolder. In most cases, the switching was successful. Switching to subfolders boosted the target audience and improved SEO ranking.

During website search engine optimization, it is important to remember that search engines use different ranking factors, each of which affects the website ranking in search results to a certain degree. 

Regardless of what website structure you choose, the most important thing is to have high-quality content that is interesting for your users, on the website. Constant content updates and improvements will help grow the target audience. 

Today, there is concrete evidence of the positive impact of subfolders, and this solution is the best for most web designers. Various reasons for the exception are discussed in this material.

Despite many conflicting statements and testimonies, it is the website owner who makes the final decision about the website structure.