Search Engine Optimization

Are Subdomains Bad for SEO?

are subdomains bad for seo

Updated on November 4, 2021

It can be difficult to understand when, or if, to add a subdomain to your website. No one wants to spend time making a substantial change, such as adding a subdomain, only to find out it’s bad for SEO. But are subdomains actually bad for SEO? Let’s dig into how subdomains impact SEO and when to use them.

What is a Subdomain?

Before we get too far into discussing how subdomains impact SEO, let’s first consider what a subdomain is.

A subdomain is a domain for your website that is part of your primary domain but has a unique identifier before the standard domain’s name. For example, the domain could have a subdomain of

Are Subdomains Bad for SEO?

Generally speaking, subdomains aren’t bad for SEO. They aren’t penalized in any way just for being a subdomain.

But they can be construed as bad because they don’t benefit the main domain or gain any benefit from it. Search engines consider them a completely separate website from the parent domain. Therefore, you need to apply SEO techniques to both the main domain and subdomain if the goal is for both sites to rank well in search engines.

So, to reiterate, there is no penalty. However, subdomains can be considered bad because they do not benefit your primary domain or receive any benefit from it.

When is a Subdomain a Good Choice?

Even though a subdomain is considered a different website and doesn’t directly benefit the primary domain, there are still a few instances where a subdomain is a good choice.

When You Want to Provide a Unique User Experience

A subdomain is a great option when you want to create a unique experience. Suppose you need a layout with different navigation, a different header, or even different screen sizes and widths. In that case, a subdomain will let you create a unique template and experience.

A subdomain can be handy for creating a website that functions like an app. It works well for any type of tool or logged-in experience as well. People sometimes use this tactic to create a mobile website, though responsive design or AMP are now the preferred methods.

If You Have Content that is Truly Off-Topic for Your Main Domain

If you have content that is off-topic for your main domain, it could make sense to put that in a subdomain. That’s because, if the content is off-topic, you’ll need to optimize the pages for keywords that are entirely different from your main domain, anyway. Therefore, even if that content were on the main domain, there wouldn’t be as much benefit, and it could even dilute the SEO efforts on your main site. If you start adding off-topic content to your main website, it will make it more difficult for people and search engines to understand the website’s purpose.

Different Geographic Regions

The last reason a subdomain could be a good choice is if you cater to different geographic regions. For that, you need variations of your website for the different audiences. In that case, it could be a good option to leverage multiple subdomains to provide content tailored to the audience that will view it.

In Summary

The key thing to remember is that a subdomain is essentially a different website. If what you’re building is part of (and should benefit) your main website, then don’t use a subdomain. If the content is associated but requires a standalone site for one of the reasons above, then go ahead and build a subdomain. There is no SEO penalty, but it’s important to understand how to adjust your existing SEO strategy to ensure the content people need to see ranks well.

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About the Author

Jennifer Rogina is the Co-Founder & Lead Marketer of ClearPath Online, a DIY SEO tool for entrepreneurs to grow their own website traffic. Jennifer has been a digital marketing specialist since 2008. In that time she has focused on search engine optimization, digital analytics, and conversion optimization.



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