Subdomains vs. Subdirectories: Understanding Their SEO Impact & Which to Use

When it comes to setting up a website, one small decision can have a big impact on how well your content performs online: Should you use a subdomain or a subfolder?

If those two terms sound a bit technical, don’t worry—we’re going to tackle everything you need to know about subdomains vs. subfolders. By the end of this article, you’ll know exactly what each one means, how they affect SEO, and which one might be better for your site.

What Are Subdomains and Subfolders?

These are two ways of creating different categories of content within your website structure.

Let’s make this super simple by comparing your website to a house.

Subfolders: Like Rooms Inside One Big House

Think of a subfolder as a room inside your house. It’s a section of your main website and lives under the same roof (domain).

For example:

• seo-hacker.com/products/
• seo-hacker.com/articles/
• seo-hacker.com/services/

All of these are just different parts of the same website. They’re often used to house all related content together. Using an example from above, all of your product pages could be found under example.com/products/, so it would look something like:  

• seo-hacker.com/products/product-1/
• seo-hacker.com/products/product-2/
• seo-hacker.com/products/product-3/

This structure keeps similar pages connected in a way that’s easy for Google to understand. So when one part of your site gets stronger (like when your landing pages gain links or attention), the rest of your site benefits too.

Subfolders are great when you want all your content to support one main site. 

Subdomains: Like a Separate House on the Same Lot

Now imagine you build a second house on your property. It’s still yours, but it’s separate from the main house.

That’s how a subdomain works.

Examples:

• products.seo-hacker.com
• articles.seo-hacker.com
• services.seo-hacker.com

It might look similar, but search engines treat this as its own separate site. That means you’ll have to build up SEO for your subdomain independently—your main site won’t automatically benefit from the blog traffic or backlinks.

Subdomains are useful when you want to create something that feels like its own website, even though it’s part of your brand. It’s also useful for creating and organizing distinct sections of a website. Taking an example from above, I could use products.seo-hacker.com to create an ecommerce platform to sell my books and case studies. 

So… Which One Helps with SEO More?

Let’s get to the heart of it: Google tends to treat subfolders as part of your main website, and subdomains as separate websites.

So if you’re adding content like a blog or resource center to help your site rank higher on search engines, a subfolder is usually the better choice. It allows all that content and effort to contribute directly to your main domain’s SEO performance.

On the flip side, if you build that same blog on a subdomain, you’ll likely need to do extra SEO work to make it rank well—just like you would with a totally separate website.

Why Do Some Companies Still Use Subdomains?

There are times when a subdomain is actually the better option. Here are a few examples:

• Different functionality or platform: Maybe your blog is on WordPress, but your main site is built differently.
• Regional targeting: If you’re launching in different countries, subdomains like ph.example.com or us.example.com might be easier to manage.
• Branding: Some businesses want their blog or shop to feel like a separate experience from the main site.

In these cases, using a subdomain makes sense—but just remember, SEO progress might take longer because you’re building authority from scratch.

Still Not Sure Which One to Choose? 

Here’s a quick guide to help you decide between using a subfolder vs. subdomain. 

When Should You Use a Subfolder?

Most of the time, subfolders are the better option—especially if your goal is to strengthen your main site and improve its rankings. Here are situations where subfolders make the most sense:

• You’re adding a blog or resource hub to your site
• Your content is closely related to your main business
• You want to maximize your SEO impact without managing multiple sites
• You’re keeping everything under one platform or CMS

For example, if your site is about business software solutions, having example.com/blog/ helps your blog directly support your brand and boost your authority.

When Does a Subdomain Make Sense?

Subdomains aren’t always a bad idea. In some cases, they’re the better (or even necessary) choice:

• You’re using a different CMS or platform (e.g., your store runs on Shopify but your site is on WordPress).
• You’re building something very different from your main site, like a customer support portal or an ecommerce store.
• You want to target different languages or countries (e.g., fr.example.com or us.example.com).
• You need to separate branding or design between sections.

Just keep in mind: if you choose a subdomain, you may need to put in more work to get the same SEO results—building backlinks, optimizing content, and maintaining consistency.

Key Takeaway

There’s no one-size-fits-all answer when it comes to the question of using subdomains vs. subfolders. It comes down to how you want to structure your website, what’s currently on your website, and what your goals are for this new section you’re building. Either option has recommended use-cases, and if used right, both can be SEO-friendly and help you achieve your target goals.