Subdomain vs Subfolder: Which is the best SEO Strategy?

Posted By on October 15th, 2020 in Search Engine Optimisation

Ah, the age-old debate, subdomain vs subfolder. One over which many SEO professionals have had heated arguments over. 

The fact that this debate has been going on for so long means that emotions run pretty high, and making the wrong choice can lead to disastrous results if not planned correctly.

So how do you choose the right link structure for you?

Essentially, it all comes down to site hierarchy.

Subdomains and subfolders are both file structures inside your server’s directory structure.

Subdomain vs Subfolder

Subdomains and subfolders are both file locations inside of a ‘Home’ directory.

A subfolder is a child directory that falls under the parent (home) directory, as is a subdomain; however, the subtle difference is that although they are both content repositories, a subdomain is a partition of a website on the server that operates almost as an independent entity.

Fun Fact: In the stone age era of the internet, server space and memory cost more than a high-end smart TV, so server administrators would create subdomains to allocate resources across the machines they had.

What is a Subdomain?

A subdomain appears before the domain name in a URL. A subdomain can be used if sections of your website are significant enough that they need their own hierarchy.

So what are some ways that you can use a subdomain structure:


One of the most common uses of a subdomain is for a multi-regional website, whether it is international or national; the use of a subdomain structure gives you a targeted approach for your respective markets. For example, if you serve your product or service in France, you can use the subdomain: or if in Australia you can use the subdomain:


Some websites like to keep their blogs separate on a subdomain like for multiple reasons, like different design structure that’s off-brand, or want to create a distinction between content on the main section of the website and the blog.


Sometimes it does not make sense for companies to have their customer support on their main site. For example, Google is a search engine, and Google’s customer service doesn’t belong in the same business structure as its Search business line, which is why they use and not


Another famous example of a subdomain would be a company providing merchandise in addition to their product or service and is usually hosted on a subdomain structure.

What is a Subfolder?

Subfolders or subdirectories are a convenient and more intuitive way to build your website structure. They are similar to a subdomain in that it allows you to create content categorically; however, they’re set up differently on the server.

A subfolder, unlike subdomains, has no server partitioning, which means that any link juice that exists on any page flows back to the primary domain.

An example of a subfolder would be The biggest benefit of a subfolder comes in the form of keyword density, which means that all keywords come under your main domain. 

Why is this a good thing? Because the keywords and keyphrases used across the website send signals to a bot, like Google, to inform on what your site is about. The technical term for this would be Latent Semantic Indexing, which essentially means allocating the related keywords to the primary content theme of the website.

How do subdomains and subfolders affect SEO in 2020?

So one of the main reasons why this topic has been an ongoing feud between search engine optimisers is because Google’s John Mueller who stated that Google’s bot has gotten much better at identifying subdomains and allocating keywords to the root domain/URL.

Moz conducted their own research on Google’s claims looking for analytical proof that keywords were accrued by subdomains allocated to a root domain.

What Moz found was that structuring your site as a subdomain structure risks confusing search engine bots and produces unwanted results like separating a significant chunk of keywords under the subdomain or diluting your backlink profile.

So what is the best file structure strategy for SEO in 2020?

With so many different opinions, it can be difficult to choose the right file structure for your website. Based on their research, Moz and many other SEO experts concluded that subfolders are the best strategy for SEO. 

Subdirectories provide a significant number of advantages:

  • Simple and clear logical structure for search engine bots to understand.
  • All web pages and folders are located under a single primary domain, keeping the keywords allocated under the primary URL.
  • A richer backlink profile so that more authority and link equity can be attributed to the primary domain. This is an important factor that determines your website’s ranking on the SERPs.

Subdomains are still great for websites which have content that is relevant to regional sites or thematically different content from the rest of your website. 

As bots continue to evolve over time, the debate over which is best, a subdomain or subfolder, may eventually simmer down, however until that time comes, a subfolder or subdirectory structure is your best bet. 

If you’re looking for an SEO company to recommend the best file structure for your website, feel free to reach out to us on our website or send us an email at

Bruce Clay AdministratorPerson