Subdomain

Subdomain

Subdomain: blog.example.com — a part of the example.com domain.

In brief

A subdomain is the part of a domain name that comes before the main domain (e.g., blog.example.com, shop.example.com). Subdomains can technically belong to the main domain, but Google often treats them as separate sites, especially for link equity and authority.

What is a subdomain

A subdomain is a prefix before the main domain (e.g., blog.example.com). Physically, a subdomain can be on the same server or a different one, but in DNS it is configured as a separate record.

Typical use cases

blog. — for a blog or news section
shop. — for an online store
m. — for a mobile version (outdated with responsive design)
support. — for a knowledge base and support

Subdomain vs subdirectory

Google officially says that subdomains and subdirectories (example.com/blog/) rank almost equally if content quality is the same. However, in practice, subdirectories often have an advantage because they inherit authority from the main domain, while a subdomain may start from zero.

Link equity from the main domain may not automatically transfer to the subdomain.
Subdomains require separate SEO optimisation and link building.
For a blog, the choice between subdomain and subdirectory is strategic.

If you want to promote unrelated business lines, a subdomain may be justified. For a regular blog on the main site, a subdirectory is usually preferable.

FAQ

Common questions

Indirectly — links from the subdomain to the main domain are internal links. If the subdomain earns external backlinks, some weight may pass to the main domain.

Typically as separate sites. A subdomain can have its own robots.txt, sitemap, and indexing settings independent of the main domain.

Google recommends subdirectories (example.com/en/), but subdomains (en.example.com) are also acceptable. Subdirectories are easier to manage and inherit authority.

What is a subdomain

Typical use cases

Subdomain vs subdirectory

Common questions

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