What is a Subdomain?
A subdomain is a division or alias of your domain that can be used to organize your existing website into a separate site. Typically, subdomains are used if there is content that is distinct from the rest of the site. Subdomains are indicated by the section to the left of the root URL. For instance, blog.examplesite.com and shop.examplesite.com are subdomains of www.examplesite.com.
Since subdomains are used to house sections of your site that are completely different than the scope of your main site, one of the reasons businesses use subdomains is because they need different servers and software to run these separate sections of their site. If your site has an international audience, separate subdomains allow for variations in content and language specific to the geographic region, but all versions are linked together under the main site.
Advantages of Subdomains
- Search engines see subdomains as unique websites unrelated to the main domain. This could have the potential to allow subdomains you create to appear along your parent domain in search engine results pages (SERPs), pushing your competition further down in results, enhancing your authority for your product or service
- Subdomains can be used to target a specific market segment, reading group, or country
- The ability to utilize a keyword for clarity, search engine, and promotional purposes. When you use google maps, the url is formatted maps.google.com which describes it’s exact purpose.
- When used correctly, if a subdomain is created for an already existing site that ranks well, the subdomain will be indexed quickly and benefit from the main domain’s good standing.
A Disadvantage of Subdomains
Search Engines viewing Subdomains as Separate Domains. Sure, the traffic on your main site is humming along, and you’ve naturally accumulated a large amount of quality backlinks. When you establish a new subdomain, you’ll need to begin acquiring high quality backlinks that are separate from your main site. If your plan is to use separate subdomains, prepare to develop unique SEO strategies for each.
What is a Subdirectory?
A subdirectory is the part of the url that houses a specific subset of content. A website is like a filing cabinet, the folders within the cabinet would be the subdirectories of your site. Individual directories are located to the right of the domain. Example: www.examplesite.com/blog or www.examplesite.com/shop
When creating your site, subdirectories are the most straightforward way to organize related pieces of content on your site. Assets such as images or downloads would be in their own subdirectories. Or if you have an About section, there could be a folder for About, and then the pages for each person on your team would be in the about folder: www.examplesite.com/about/johndoe.html .
Advantages of Subdirectories
Using subdirectories over subdomains has several advantages when looked at for SEO purposes:
- Instead of competing with yourself with a subdomain that may have fresher content than your main domain, your focus could be on making a single website optimized.
- Your site could get crawled more often as you are constantly adding content and blog posts; because of this, the SEO authority that you have will be inherited by your primary site.
- If you have a blog post focusing on new features or products, your users can easily go between your blog and your product/service pages.
- Finally, if you are tracking your site’s performance in a platform such as Google Analytics, the data is consolidated for the entire site, rather than having to look at two data points as a result of using two domains.
A Disadvantage of Subdirectories
A potential high number of URLs. Since authority is shared across all pages, the more pages there are, the more diluted authority can get. When content in a subdirectory is not as impactful as your main content, using a subdomain could be ideal.
Which is method is preferred?
This is a somewhat debated issue, however subdirectories are generally the preferred method, Every website is different and the question of subdirectory vs subdomain should be made on a case by case basis.
To get some further insights, check out these discussion threads on Moz.com
An easy way to differentiate the two is that a subdomain is a separate site altogether from your main site while a subdirectory is a label for describing the theme or meaning of a page or group of pages on your site. Truthfully, either approach if technically executed correctly can be successful. Rather than spending too much time on which approach will give you the most results and conversions, the focus should stay on creating and maintaining a structure that makes sense for your content.
Updated: Apr 23, 2020
Since the original edition of this post, we received a number of comments asking follow up questions. The following content is intended to address the most popular questions and provide some deeper insight into the advantages and disadvantages of subdomains and subdirectories.
International SEO and its Impact on Subdomains and Subdirectories
International websites have three choices, subdomains, subdirectories, and country code Top Level Domain or ccTLD. An example of a ccTLD would be website.co.uk, which would be specific to the United Kingdom. ccTLDs are specific to countries, not languages, and are always two letters. By comparison, generic Top Level Domains or gTLDs are three letters, such as .com or .org. The ccTLD for the United States is .us, but it not often used.
By using a ccTLD, you are telling search engines that the intended audience for your site if intended to be from a specific country. Google has stated that they use ccTLDs to determine target audiences. ccTLDs are an ideal option for a business that:
- Are well established global brand continuously creating content
- Have physical locations across multiple locations
- Have the resources (budget) to create and maintain a unique site for each specific country
- Hosts a wide variety of products or services depending on geographic location
- Are aiming to host international versions of their sites on servers potentially not located in targeted countries.
Trust is a huge factor for users on sites using their country’s ccTLD, which leads to a better user experience overall. There are some considerations:
- Resources to build and maintain multiple versions of the site
- Certain ccTLDs may have restrictions
- Each site will require an individualized SEO strategy. Separate keyword research, link building, and content strategies will need to be developed for each separate site.
Using subdomains could be an option for companies that have yet to build strong international awareness and don’t have the capacity to create content filling multiple ccTLD sites. If this route is to be explored, use Search Console to geotarget each subdomain. This tactic can be used for ccTLDs, but search engines already recognize country codes as indicators to target specific regions. Subdomains are not free from effort and will require the resources to establish and maintain each separate subdomain.
You can probably determine how subdirectories factor in as an option. Using one gTLD, content can be stored in separate folders for each country or language. Since all folders are on the TLD, any link authority you’ve previously gained can be used in your favor. Using Search Console, you can geo-target each folder. Subdirectories are ideal if you don’t have the resources for ccTLDs or subdomains for every country and language you’re targeting. Subdirectories are not as strong of a signal to search engines as ccTLDs. If your efforts to geotarget sites in the same language, you could accidentally rank the wrong version.
URL parameters is another option that you could pursue. While possible to set up your site using URL parameters to determine language or region, there are no benefits and even more flaws to work through; Geotargeting with Search Console is not possible, separating visitors based on parameters is time-consuming, and with well-structured URLs being critical to SEO, a confusing URL is a benefit only to your competitors.