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How subdomains impact SEO

What You Need to Know About Subdomains

A website can be structured with a main website and subdomains. Subdomains may be problematic for SEO, analytics and user experience. This article examines how to identify possible implications for your website’s success, and what to do about it. 

What are subdomains?

A primary website is called a domain. It has a domain name eg. “”. Subdomains are separate entities from the primary domain and are created to help arrange and navigate the different sections of your website. Each subdomain has a distinct name, eg. “”.

There are several reasons why subdomains are used, including:

  • Site testing
  • A separate eCommerce site
  • A mobile-specific site
  • Location-specific sites
  • Demographic targeting
  • Efficient site organisation and navigation (in some cases)

If you are using subdomains to target specific locations or audiences, consider your SEO and SEM strategies. Foe example, consider focusing on different keywords for each subdomain. (In this instance, subdomains may be helpful to your overall digital strategy). 

Digital audit to identify any issues

While sometimes beneficial, subdomains, if not set up correctly, may start competing with your main website and impact your site’s domain authority score. 

The best way to determine whether your subdomain structure is problematic (or advantageous) to your business’s digital health is with a website audit. An independent digital audit reviews your entire digital footprint and can determine whether there are any factors impacting your website’s success. Your audit report will also provide advice on ways to improve or correct any issues. 

SEO, and How Google views subdomains

In some cases, depending on how the subdomain is set up, subdomains may be treated by Google as separate sites. This means that search engines will have to crawl and index subdomains separately from the main site. This has several consequences. 

Subdomains do not inherit the primary domain’s SEO advantages. Depending on how subdomains are set up, they may require separate link-building time and resources. Essentially, it’s double the work, because you’re building SEO ranking for two (or more) separate sites. It can also harm Google ranking indicators.

In some circumstances, a primary domain and subdomain may even be competing against each other for a higher ranking. If the main domain and subdomains are optimised for the same keywords there is a chance that the subdomain may outperform the main domain, and negatively impact SEM efforts. 

Unifying subdomains

It is possible to transition from a subdomain to a subdirectory structure, by unifying your subdomains to the main site. Doing so may enhance:

  • The ability to understand, control, create and benefit from quality backlinks
  • User experience.  A unified user experience helps reduce bounce rates, optimising the user journey and increasing conversions
  • SEO and SEM outcomes such as increasing organic and paid search traffic, and improving search engine ranking
  • Analytics tracking

If unifying your sub-domains is unattainable in the short term, it is highly recommended to add your subdomains to Google Search Console. This will allow you greater visibility, and improved performance on search rankings, keywords, and ongoing maintenance.

Contact us to learn about your website’s structure and how it may be impacting your success. Our friendly team is here to help you reach your business goals.