Subdomains vs Subdirectories for SEO (2025)

Quick Answer

Table of Contents

Understanding the Difference

Before diving into SEO implications, let's clarify the structural difference between subdomains and subdirectories.

What Is a Subdomain?

A subdomain is a prefix added before your main domain name, creating what functions as a separate website:

blog.example.com
shop.example.com
support.example.com

Subdomains have their own DNS records and can point to entirely different servers. From a technical standpoint, each subdomain operates as an independent entity with its own:

• Separate crawl budget allocation
• Independent Google Search Console property
• Distinct backlink profile
• Individual domain authority metrics (in third-party tools)

What Is a Subdirectory?

A subdirectory (also called a subfolder) is a path that comes after your main domain:

example.com/blog
example.com/shop
example.com/support

Subdirectories exist within your main domain's structure. All content in subdirectories:

• Shares the same crawl budget
• Lives under one Google Search Console property
• Contributes to a unified backlink profile
• Builds collective domain authority

The Structural Impact

Consider this analogy: A subdomain is like opening a second store across town with a different address, while a subdirectory is like adding a new department within your existing store. Both can sell the same products, but customers (and search engines) perceive them differently.

Google's Official Position

Google has addressed the subdomain vs. subdirectory debate multiple times, with John Mueller, Google's Search Advocate, providing the clearest guidance.

John Mueller's Direct Statements

In official Google communications and webmaster hangouts, John Mueller has stated:

"From our point of view, when we talk with the search quality team, they say subdomains and subdirectories are essentially equivalent. You can put your content however you want."

He further clarified:

"Google Web Search is fine with using either subdomains or subdirectories. Setting up parts of a website as subdirectories is fine for us. This helps us with crawling since we understand that everything's on the same server and can crawl it in a similar way."

Regarding subdomains specifically:

"Putting website sections in separate subdomains also works for us. We do have to learn to crawl them separately, but for the most part, that's just a formality for the first few days."

Mueller's Personal Recommendation

Despite Google's official neutrality, Mueller has expressed a personal preference:

"I would personally try to keep things together as much as possible. So if it's the same site then try to put them on the same site, essentially, and use subdomains where things are really kind of slightly different."

What This Means for You

Google's algorithms don't inherently favor one structure over the other. However, the practical implications of each choice can affect your SEO outcomes:

1. Subdirectories are easier to crawl because Google understands all content is on the same server
2. Subdomains require separate learning as Google needs to crawl and understand them independently
3. Both can rank equally well with proper optimization

How Google Treats Subdomains

Understanding how Google actually processes subdomains reveals important SEO considerations.

Separate Search Console Verification

Google requires you to verify subdomains separately in Google Search Console. Each subdomain needs its own property:

• www.example.com - one property
• blog.example.com - separate property
• shop.example.com - separate property

This separate verification indicates that Google tracks and evaluates subdomain performance independently, even while recognizing their relationship to the main domain.

Independent Crawling

Google's crawlers treat subdomains as distinct entities that need to be:

1. Discovered separately
2. Crawled with their own budget allocation
3. Indexed independently
4. Ranked based on their own signals

As Mueller noted, Google has to "learn to crawl them separately," which means:

• New subdomains start without established trust signals
• Crawl priority may differ from the main domain
• Index coverage builds independently

Domain Authority Relationship

While third-party metrics like Moz's Domain Authority or Ahrefs' Domain Rating aren't Google ranking factors, they illustrate an important principle: link equity distribution.

When you create a subdomain:

• Third-party tools often show it starting with zero authority
• The main domain's authority doesn't automatically transfer
• Each subdomain must build its own backlink profile

This reflects how search engines generally perceive the relationship between subdomains and parent domains.

Link Equity and Domain Authority

The most significant practical difference between subdomains and subdirectories lies in how link equity (also called "link juice") flows through your site.

Subdirectory Link Equity

With subdirectories, link equity works straightforwardly:

External Site → example.com/blog/great-article
                    ↓
         Benefits example.com directly

When another website links to any page in your subdirectory:

• Direct benefit: The link strengthens your main domain
• Internal distribution: Link equity flows through internal links to other pages
• Cumulative effect: All content contributes to overall domain strength

Subdomain Link Equity

With subdomains, the link equity path is more complex:

External Site → blog.example.com/great-article
                    ↓
         Benefits blog.example.com
                    ↓
         Indirect benefit to example.com (if any)

When sites link to your subdomain:

• Primary benefit: The subdomain receives the link equity
• Limited transfer: Some signals may pass to the main domain, but not directly
• Separate building: Each subdomain must earn its own authority

Practical Example

Imagine your blog receives 100 backlinks over a year:

Subdirectory Structure (example.com/blog):

• 100 backlinks directly strengthen example.com
• Your main domain benefits from every piece of content
• Product pages, services, and other content gain indirect benefit

Subdomain Structure (blog.example.com):

• 100 backlinks strengthen blog.example.com
• Your main domain (example.com) may see indirect benefits
• Product pages must build their own backlink profile separately

This difference explains why many SEO case studies show improved performance after consolidating subdomains into subdirectories.

When to Use Subdirectories

Subdirectories are the recommended choice for most websites and most content types.

Best Use Cases for Subdirectories

1. Company Blogs

Your blog should almost always be a subdirectory:

example.com/blog

Why:

• Blog content builds authority for your entire domain
• Internal linking from blog posts helps all pages
• Easier content management and site architecture
• Single analytics and Search Console property

2. Resource Centers and Help Documentation

example.com/resources
example.com/help
example.com/docs

Educational content that supports your main business belongs in subdirectories to strengthen overall domain authority.

3. Category Pages and Product Sections

example.com/products
example.com/services
example.com/solutions

Core business content should always consolidate under your main domain.

4. Landing Pages

example.com/landing/campaign-name
example.com/offers/special-deal

Campaign landing pages benefit from your domain's existing authority.

5. Localized Content (Same Language)

example.com/uk
example.com/au

Regional variations of the same-language content work well as subdirectories with proper hreflang implementation.

The Consolidation Advantage

Keeping content in subdirectories provides:

• Unified authority building: Every piece of content strengthens the whole
• Simplified management: One Search Console property, one analytics view
• Cleaner internal linking: Easier to create effective site architecture
• Consistent branding: Users experience one cohesive site
• Efficient crawling: Google understands your site structure faster

When to Use Subdomains

Despite the general recommendation for subdirectories, subdomains make sense in specific scenarios.

Legitimate Use Cases for Subdomains

1. Different Technology Platforms

When sections of your site require entirely different technology stacks:

www.example.com (WordPress)
app.example.com (React application)
docs.example.com (Documentation platform like GitBook)

Running different platforms on the same subdirectory structure requires complex reverse proxy configurations. Subdomains simplify this significantly.

2. User-Generated Content Platforms

Sites hosting user content often use subdomains to:

• Isolate potentially risky content from the main domain
• Provide users with their own space
• Implement different security policies

Examples:

username.example.com
project.example.com

This is common for platforms like Tumblr, WordPress.com, and Medium.

3. Geo-Targeted International Sites

For multinational businesses targeting different countries with different languages:

de.example.com (German site)
fr.example.com (French site)
jp.example.com (Japanese site)

While ccTLDs (country-code top-level domains) are often preferred, subdomains provide a middle-ground solution that:

• Allows separate content management
• Enables different hosting locations for speed
• Simplifies geo-targeting in Search Console

4. Completely Different Products or Services

If your company operates distinct product lines that target entirely different audiences:

enterprise.example.com (B2B enterprise software)
consumer.example.com (B2C consumer app)

When the audiences, content, and marketing are entirely separate, subdomains can make organizational sense.

5. Development and Staging Environments

staging.example.com
dev.example.com
beta.example.com

These should always be subdomains (and typically blocked from indexing).

The Subdomain Trade-Off

Using subdomains means accepting:

• Separate authority building for each subdomain
• More complex analytics and reporting
• Independent Search Console properties
• Potential for inconsistent SEO optimization
• More technical overhead for DNS and SSL management

Real-World Case Studies

The subdomain vs. subdirectory debate has been tested by numerous companies. Here are documented results from migrations.

Successful Subdirectory Migrations

Salesforce One of the most cited examples in SEO circles. When Salesforce moved their blog from a subdomain to a subdirectory, they reported traffic doubling overnight. This dramatic result demonstrated the immediate benefit of consolidating content authority.

Flick After migrating content from a subdomain to a subdirectory and implementing comprehensive SEO improvements, Flick reached 9.6 million yearly traffic within 12 months.

Chubo Knives This e-commerce site saw a 421% increase in organic traffic after migrating their blog subdomain content into a subdirectory on their main site.

Monster.com Monster.com's UK site (Monster.co.uk) increased visibility by 116% after migration. Their German site also saw significant traffic increases.

Pink Cake Box After moving their blog from a subdomain to a subdirectory in 2015, organic traffic to their primary domain increased by 40%.

The Reverse: Subdirectory to Subdomain

Iwantmyname (2014) In a telling counter-example, Iwantmyname experimented with moving their blog from a subdirectory to a subdomain. The result: a 47% decrease in organic traffic. This provided clear evidence of the consolidation advantage.

Important Caveats

When evaluating these case studies, consider:

1. Correlation vs. causation: Many migrations coincide with other SEO improvements
2. Time period matters: Older case studies may not reflect current algorithm behavior
3. Implementation quality: Poor migrations can hurt either structure
4. Industry differences: Results vary by niche and competition level

Ahrefs' analysis of Mention.com's migration found no immediate difference in the migration period itself, with growth only occurring after they began adding additional content. This suggests that content quality and quantity matter more than structure alone.

Technical Implementation Considerations

Choosing between subdomains and subdirectories involves practical technical factors beyond SEO.

SSL Certificate Management

Subdirectories: One SSL certificate covers everything

*.example.com requires just one certificate for www

Subdomains: Require either:

• Wildcard SSL certificate (*.example.com)
• Individual certificates for each subdomain
• Additional cost and management overhead

Server Configuration

Subdirectories (Apache/Nginx):

# Simple configuration - all routes served by same virtual host
DocumentRoot /var/www/example.com
<Directory /var/www/example.com/blog>
    # Blog-specific settings
</Directory>

Subdomains (Apache/Nginx):

# Requires separate virtual host configuration
<VirtualHost *:443>
    ServerName blog.example.com
    DocumentRoot /var/www/blog
</VirtualHost>

Content Delivery Networks (CDNs)

Subdirectories: Simple CDN setup with one origin

CDN → example.com (all paths)

Subdomains: May require multiple CDN configurations

CDN Config 1 → example.com
CDN Config 2 → blog.example.com
CDN Config 3 → shop.example.com

Platform Integration

Some platforms make certain structures easier:

Shopify: Natively supports subdomains for additional storefronts HubSpot: Historically required subdomains for blogs on external sites WordPress Multisite: Supports both but subdomains are simpler to configure

DNS Requirements

Subdirectories: Require only the main domain's A/CNAME records

Subdomains: Require additional DNS records for each:

blog.example.com    A     192.0.2.1
shop.example.com    A     192.0.2.2
app.example.com     CNAME app-server.hosting.com

You can use DomainDetails domain lookup to inspect the current DNS configuration of any domain, including all subdomain records.

Migration Best Practices

If you're planning to migrate from subdomains to subdirectories (or vice versa), follow these practices to minimize SEO impact.

Before Migration

1. Audit Current Performance Document baseline metrics:

• Organic traffic to each subdomain
• Ranking keywords and positions
• Backlink profile (use Ahrefs, Moz, or similar)
• Indexed pages in Search Console

2. Map All URLs Create a comprehensive mapping document:

Old URL                              →  New URL
blog.example.com/post-title         →  example.com/blog/post-title
blog.example.com/category/seo       →  example.com/blog/category/seo

3. Lower TTL Values Before migration, reduce DNS TTL to 300 seconds (5 minutes) at least 24-48 hours in advance. This ensures faster propagation of changes.

During Migration

1. Implement 301 Redirects Use permanent (301) redirects for every URL:

# Apache .htaccess
RewriteEngine On
RewriteCond %{HTTP_HOST} ^blog\.example\.com$ [NC]
RewriteRule ^(.*)$ https://example.com/blog/$1 [R=301,L]

# Nginx configuration
server {
    server_name blog.example.com;
    return 301 https://example.com/blog$request_uri;
}

2. Update Internal Links Change all internal links to point to new URLs. Don't rely solely on redirects.

3. Update XML Sitemaps

• Remove old subdomain sitemap
• Add new subdirectory URLs to main sitemap
• Submit updated sitemap to Search Console

After Migration

1. Verify in Search Console

• Add the new subdirectory structure to your property
• Monitor for crawl errors
• Use URL Inspection tool to verify redirects

2. Monitor Indexing Check that:

• Old URLs are being removed from the index
• New URLs are being indexed
• No duplicate content issues arise

3. Track Ranking Changes Expect some fluctuation for 2-4 weeks. According to practitioners, traffic typically rebounds within 1-2 months for well-executed migrations.

4. Update External Backlinks Reach out to high-value linking sites to update their links to your new URLs (though 301 redirects will preserve most value).

The Verdict for Most Use Cases

After examining Google's official position, real-world case studies, and practical considerations, here's the clear recommendation:

For Most Websites: Use Subdirectories

Choose subdirectories when:

• Your content is related to your main business
• You're building a blog or resource center
• You want to maximize SEO efficiency
• You prefer simpler technical management
• You have one main target audience

The Exception: Specific Subdomain Use Cases

Choose subdomains when:

• Running entirely different platforms (app vs. marketing site)
• Hosting user-generated content that needs isolation
• Operating distinct international sites
• Sections are truly independent businesses
• Technical requirements make subdirectories impractical

Why This Matters

While Google says they're equivalent, the practical reality differs:

1. Link equity flows more efficiently in subdirectories
2. Authority builds faster with consolidated content
3. Management is simpler with unified structure
4. Case studies consistently show subdirectory advantages

The SEO industry has largely reached consensus: for most websites, subdirectories are the better choice. The case studies showing 40-421% traffic increases after consolidation provide compelling evidence that structure does matter, even if Google's algorithms are theoretically neutral.

Frequently Asked Questions

Does Google see subdomains as separate websites?

Google doesn't officially call them "separate websites," but they do require separate verification in Search Console and crawl them independently. The practical effect is that subdomains start without the trust and authority signals of your main domain.

Can a subdomain rank for the same keywords as the main domain?

Yes, but this can create internal competition. If your subdomain and main domain target the same keywords, you might split your ranking potential. Subdirectories avoid this issue entirely.

How long does it take to see results after migrating to subdirectories?

Most migrations see initial fluctuation for 2-4 weeks, with traffic typically recovering and often improving within 1-2 months. The Salesforce case showed immediate doubling, but results vary.

Should my e-commerce store use a subdomain for the blog?

No. E-commerce blogs should almost always be subdirectories. Blog content builds authority that helps product pages rank better. The Chubo Knives case study showed 421% traffic increase after this migration.

Do backlinks to a subdomain help the main domain?

Indirectly, yes, but not as much as backlinks to subdirectories. Links to subdirectories directly strengthen your main domain's authority, while subdomain links primarily benefit the subdomain itself.

Is it worth migrating an established subdomain to a subdirectory?

If your subdomain has built significant authority over years, carefully weigh the migration costs against potential benefits. For newer subdomains or those not performing well, migration often makes sense.

Can I use both subdomains and subdirectories?

Yes, many sites do. You might have app.example.com for your web application while keeping your blog at example.com/blog. Use each where it makes the most sense.

Does Google Search Console treat them differently?

Yes. Subdirectories appear under your main domain property, while subdomains require separate verification and appear as distinct properties.

Key Takeaways

• Google officially treats subdomains and subdirectories equally, but practical outcomes often differ due to link equity distribution and crawling behavior
• John Mueller personally recommends keeping content together in subdirectories when possible
• Case studies consistently show traffic increases (40-421%) after migrating from subdomains to subdirectories
• Subdirectories consolidate domain authority, making them more efficient for SEO
• Use subdomains only when necessary: different platforms, user-generated content, geo-targeting, or truly independent products
• Migrations require careful planning with proper 301 redirects, URL mapping, and monitoring
• For most websites, subdirectories are the clear winner for blogs, resources, and business content

Next Steps

Immediate Actions

1. Audit your current structure: Identify all subdomains and evaluate if they should be consolidated
2. Review your blog setup: If it's on a subdomain, consider migration planning
3. Check your Search Console properties: Understand how Google currently views your site structure

Related Reading

• What Is a Subdomain? - Understand subdomain fundamentals
• DNS Record Types Explained - Learn how DNS records power subdomains
• How Do Domain Names Work? - Foundation knowledge for site architecture

Tools to Use

• DomainDetails: Research competitor domain structures and DNS configurations
• Google Search Console: Monitor indexing and performance for both structures
• Screaming Frog or Sitebulb: Audit your current URL structure and internal linking

Research Sources

• Google Search Central documentation on site structure
• John Mueller statements in Google Webmaster Hangouts and Twitter
• SE Ranking subdomain vs subdirectory research study
• Ahrefs analysis of subdomain migration case studies
• Salesforce, Flick, Monster.com, and Chubo Knives documented migration results
• Cloudflare engineering blog on subdomain best practices