Subdomains for SEO: Should You Use Them? Why & Why Not

Explore the intricacies of using subdomains for SEO, their comparison with subdirectories, and how their strategic use can impact your business goals and link-building efforts.

Kayla Johansen Digital Marketing Specialist
October 25, 2023
6 min. read

If you’re thinking about creating a subdomain for your site, you’ll first want to make sure it suits your business. While subdomains can work well for some companies, depending on their SEO goals, a subdirectory is often a better choice for search engine optimization.

But there’s much more nuance to the subject than that, so let’s dive in deeper. On this page, we’ll discuss:

What a subdomain is and how it differs from a subdirectory
When you should use a subdomain
Whether subdomains are bad for SEO
Why a subdomain blog isn’t always a good idea

Ready to determine what’s best for your business? Let’s go!

Free domain overview

What is a subdomain?

A subdomain is an add-on placed at the beginning of your primary domain name, such as blog.mysite.com. The subdomain creates a distinct section of your site that remains connected to your primary URL.

The subdomain will maintain your branding and continue to be associated with your main site from a user perspective, but otherwise, it’s largely on its own.

Subdomain vs. subdirectory

The primary difference between a subdomain and a subdirectory is that the subdirectory is a folder housed within your main site, while a subdomain is a distinct section.

The URL for a subdirectory will look like: mysite.com/blog, with “blog” being the subdirectory.

Should you use subdomains?

Whether you should use subdomains depends on your business goals and what you plan to use the subdomain for. Some companies might use subdomains to:

Target different countries or languages, like for international SEO
Host content related to sub-brands or topical niches
Test and stage new pages that are in development

For developers, a subdomain can be an easy way to preserve the site’s link structure while they test new designs or sections of a website. Because the subdomain is a distinct section of the main domain, they can keep it private and password protected.

But what about live versions of a site? A subdomain can be useful if you have a specific purpose for the content that differs from the primary domain.

For example, perhaps you own a restaurant and want to create a pop culture blog (who knows, maybe it’s appealing to your target audience!). Because the blog’s topic is completely separate from the restaurant, you could consider publishing it on a subdomain.

Large corporate brands use subdomains a lot for their various sub-brands.

For example, Apple does this with its streaming service, which they host at tv.apple.com. Healthcare companies may take a similar approach, like having a subdomain for information or activities specific to insurance providers.

Google also uses subdomains extensively. For example, maps.google.com takes you to Google Maps, and support.google.com provides access to their customer support. This helps Google organize its services and provides users with direct access without cluttering the main google.com domain.

Are subdomains bad for SEO?

Subdomains aren’t directly bad for SEO, but they’re not always the most strategic choice. Google states that subdomains and subdirectories are both fine, but subdomains are crawled and tracked separately.

Your subdomain will likely be on its own for SEO factors like link equity, and it probably won’t pass link equity onto your main domain, either.

“Google websearch is fine with using either subdomains or subdirectories…I recommend picking a setup that you can keep for longer.”

John Mueller, Google Source

Because link building can be one of the most challenging — and most vital — aspects of your SEO strategy, you’ll want a really good reason to choose a subdomain over a subdirectory.

For example, if the subdomain’s topic is totally different from the main domain, a relevant backlink profile would also look completely different. In this case, a subdomain could work well.

Keeping the new topic separate from the main site could help you build an SEO strategy specific to that niche, including its relevant keywords. Meanwhile, positioning it as a subdomain instead of an all-new domain allows you to maintain your brand equity.

Why a subdomain blog is usually a bad idea?

However, if you’re considering placing your blog on a subdomain, you might want to think twice. If the blog’s content is relevant to your main site, you could miss out on powerful link-building opportunities by placing it on a subdomain.

Informative, helpful content, as you find on a blog, often generates ample links. If you want your main site to benefit from these hard-earned links, you’ll likely want to post your blog in a subdirectory on the primary site instead.

Beyond SEO considerations, subdomains can also significantly impact user experience, and not always in a positive way. Here’s how:

Perceived separation

Subdomains can sometimes create a sense of separation from the main brand:

Users might see the subdomain as a distinct website, leading to a sense of unfamiliarity, especially for new visitors.
This can weaken brand recognition if the subdomain’s connection to the main brand isn’t immediately obvious. Consistent branding helps mitigate this.
Inconsistent visual branding, such as different logos or color schemes, amplifies this perceived separation, making the experience feel disjointed and less trustworthy.

Disrupted user journey

Subdomains can also lead to a disrupted user journey:

Sudden changes in URL and design when navigating to a subdomain can interrupt the user’s browsing flow, creating a jarring experience for them.
Unfamiliar navigation on the subdomain, compared to the main site, can confuse users and hinder their ability to easily find information and complete their goals.
These disruptions can increase bounce rates and reduce overall engagement, as users may simply leave if the experience becomes too frustrating or confusing.

Mobile experience complications

Subdomains can sometimes present mobile experience complications:

Subdomains might lack full optimization for mobile devices, resulting in a subpar experience for mobile users, which is a significant concern today.
Mobile users may face slower loading speeds on the subdomain, which can be particularly detrimental to mobile connections and lead to abandonment.
A non-responsive design can cause usability issues on smaller screens, making it difficult to read content and navigate effectively, impacting overall satisfaction.

Ultimately, while subdomains can serve a purpose in specific situations, it’s important to carefully weigh the potential impact on both SEO and user experience. A well-thought-out strategy, considering both technical and user-centric aspects, is essential for making the right decision and ensuring a cohesive online presence.

Choose a subdomain only if it suits your business strategy

Ultimately, a subdomain can suit certain business needs well, but going that route requires a thorough understanding of the pros and cons (or having an SEO company that does). Unnecessary subdomains can over-complicate your SEO strategy, but sometimes, you need to distinguish one part of your business from another.

Navigating the complexities of subdomains and subdirectories can be challenging, but you don’t have to do it alone. Our expert team is here to help whether you’re considering a subdomain or looking to optimize your entire site. Contact us online today!

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Kayla is a content specialist with a B.S. in marketing. She is certified in Google Analytics and Google Ads Search and Display. When not writing, she enjoys reading, playing with her dog, and baking.