Subdomain vs Subdirectory for SEO Localization

Chidinma Egwuogu
17 May 2024

8 min. read


The "subdirectory vs. subdomain debate is a perennial head-scratcher for website owners. And even more so for owners of localized websites.

Today, I’ll try to put the issue to rest and help you choose the best option for your multilingual website.

Let’s dive in.

Subdomain or subdirectory for SEO localization?

The bold part here is a subdomain. You could use it to create an Italian version of a sprawling website. It will require separate hosting and substantial maintenance.

But of course, your scenario might differ.

The URL part highlighted in bold here is a subdirectory. You might use it for smaller localization projects. Especially, if your budget is tight.

Now that you have a basic understanding of subdomains and subdirectories, let’s explore them in finer detail.

What is a subdomain in localized websites?

A subdomain is a prefix before your main domain, serving as a separate section within your website's overall domain hierarchy. In multilingual SEO, subdomains help organize and separate content for different locales.

To remember the domain vs subdomain distinction, think of the subdomain as a mini-website. It rests under the umbrella of the main domain and is treated as a distinct entity by search engines.

Here’s a subdomain example: a subdomain structure example

A subdomain URL consists of a third-level domain that appears before your main website's domain name, which is followed by a top-level domain name.

Let’s break it down.

  • Subdomain comes before the main domain name, separated by a dot. For example, or
  • Main domain is the core website address, like google or wikipedia.
  • Top-level domain (TLD) like .com, .org, or .ca indicates the website type or geographical location.

Note: You can also have subdirectories under a subdomain.

How subdomains work for SEO localization

Subdomains can be particularly useful for SEO localization because they allow businesses to cater content specifically to different regions or languages.

For instance, using for French-speaking visitors.

This clear delineation can help search engines understand and index translated content targeted at specific geographic or language groups.

Pros of using subdomains

  • Flexibility: Subdomains allow for the customization of content and design for different user segments or marketing campaigns without affecting the main website.
  • Targeted SEO: You can implement specific SEO strategies tailored to each subdomain.
  • Stronger visual separation: Subdomains offer a distinct visual identity for each language version.
  • Isolation of risk: If anything bad happens to a subdomain (a hack or downtime), it doesn’t necessarily impact the main domain.

Cons of using subdomains

  • SEO effort duplication: Subdomains don’t inherit the full SEO authority of the main domain because search engines treat a subdomain as a new website. This can make it harder for new websites to rank initially.
  • Resource intensive: Prepare to face additional hosting costs and web development resources when setting up and managing separate sub-domain websites. Also note, that some SEO and CMS tools might bill you per domain name.

What is a subdirectory in localized websites?

A subdirectory, or a subfolder, acts like a designated file section in the URL structure hierarchy of your main domain. It helps organize content under one domain, maintaining a neat and well-structured website hierarchy.

A key difference between subdomains and subdirectories is that subdirectories maintain the main domain as the central hub, whereas subdomains act like independent websites under the same brand.

Consider a subdirectory example:

Here, the subdirectory URL structure is quite straightforward:

a subdirectory structure example

  • Main domain or root domain is the central hub of your website.
  • Top-level domain (TLD) like .com specifies the website's category or purpose.
  • Subdirectory is a folder under the main domain, dedicated to a specific location.

How subdirectories work for SEO localization

Subdirectories are beneficial for SEO localization as they consolidate all SEO efforts under a single domain. This pools and shares your domain authority to boost rankings across various regions.

For instance: By using language-specific subdirectories, like “…” for German, a multilingual website can efficiently target different linguistic groups without losing their earned authority.

Pros of using subdirectories

  • Shared authority: Link equity and other SEO benefits are shared across the entire domain and help rank faster from the start for each local subdirectory.
  • Simplified management: Easier to manage as everything falls under one domain.
  • Clear user experience: Users typically understand the subdirectory structure, knowing they're still on the same website with content organized in different sections.
  • Cost-effective: Generally, subdirectories are less costly to set up and maintain compared to subdomains, as they require fewer hosting and development resources.

Cons of using subdirectories

  • Limited flexibility: Not as flexible as subdomains in terms of design and functionality customization for different site sections.
  • Potential for content overlap: Risk of content and keyword cannibalization if not structured properly, which can dilute SEO efforts.
  • Potential for clutter: Can lead to a crowded site structure if not organized properly, impacting user experience.
  • Complex navigation for large sites: For very large sites, subdirectories might complicate site navigation and user experience due to the depth of the site structure.

Google’s stance on subdomain vs subdirectory debate

Google’s Webmaster Trends Analyst, John Mueller, has settled the subdirectory vs subdomain SEO debate, clarifying that Google can effectively crawl and index both.

Mueller emphasizes that either structure can work well, depending on how they are implemented and maintained:

Google Web Search is fine with using either subdomains or subdirectories…use what works best for your setup and think about your longer-term plans when picking one or the other.

Case studies on subdomain and subdirectory usage

Despite Google’s neutral stance, industry experts often share contrasting views. Generally, subdirectories are favored because they inherit the authority of the main domain, potentially boosting SEO performance.

Real-world case studies also show that subdirectories may be advantageous in certain contexts. For example: This site saw significant improvements in visibility after moving from subdomains to subdirectories. This change was accompanied by increased organic traffic, even when replicated on their German site.

Before moving from
ahrefs data 1

After moving to
ahrefs data 2 Moving Pinterest from a subdomain to a subdirectory, gave it a tremendous organic traffic boost in 2017.

Before moving from

ahrefs data 3

After moving to

ahrefs data 4

These case studies are pretty compelling; however, there’s a caveat.

Several variables could have influenced the spikes in visibility. Usually, companies engage in better keyword research and increased content production after the subdirectory migration.

The caveat muddies the results, but worry not, we will help you choose the winner in the subdomain vs subdirectory battle.

Choosing the right option for your website

While SEO plays a crucial role, it's not the only factor to consider when choosing between subdirectories and subdomains for your multilingual website. Here are some additional factors to keep in mind.

Use subdirectories if:

  • Your budget is tight. Subdirectories don’t require separate hosting.
  • Your technical team is limited. Subdirectories are easier to manage since they fall under the same domain and share settings and analytics.
  • You don’t have plans to scale your business significantly or expand globally

Use subdomains if:

  • You want to offer a clear distinction between numerous languages, locations or culturally distinct audiences.
  • Your content requires significant localization
  • You need separate management teams for localized content.
  • Building a strong SEO presence for each version is a goal.

Additional considerations:

  • Website size and complexity: Consider subdomains for easier separation if you have a large, complex website structure.
  • User experience: Prioritize user experience—subdirectories for similar content, subdomains for distinct languages.

Remember, there's no one-size-fits-all approach. Carefully analyze your website's goals and resources to choose the structure that best supports your long-term multilingual SEO strategy and user experience.

Parting thoughts

Google doesn't have a clear favorite. But if a subdirectory fits your purpose, it’s best to use it. They generally offer a slight SEO advantage due to the potential inheritance of link equity from the main domain.

Ultimately, choosing between a subdomain and a subdirectory depends largely on your specific business needs, technical requirements, and future growth plans.

Whatever you choose, local SEO requires more than a new URL structure. You will need to adapt content, localize keywords, and ensure cultural relevance. You will need a translation management system.

And that’s where Centus steps in.

Centus editor

We can help you with:

  • Machine translation with human review: Automatically translate large volumes of content and ensure quality with human oversight.
  • Collaborative tools: Bring your teams together on one platform. Everyone from developers to translators can add context, track progress, and exchange feedback, ensuring everyone is aligned and informed.
  • Support for multiple file formats: Effortlessly manage multiple file types in one place, making it easier for developers, designers, and translators to access and use them.
  • Third-party integration: Centus integrates smoothly with popular tech stacks, including Figma and GitHub, to streamline your workflow and keep you productive.

With localization tasks handled, you can focus on building your global brand and perfecting your multilingual SEO.

Try Centus now!

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