Set up a subdomainFree, as many as you like - and what they are worth it for

Published on October 20, 2026

What a subdomain is

A subdomain is everything to the left of your registered domain. yourcompany.com becomes shop.yourcompany.com, blog.yourcompany.com or mc.yourcompany.com.

The crucial point: subdomains are not registered. They come into being solely through a record in your DNS zone. That means they cost nothing, are available immediately and there is no limit - even test.staging.yourcompany.com is possible.

Creating one: a single record is enough

In DNS management, you create a record whose name is the subdomain. Two variants are common:

shop    A       85.214.12.7
blog    CNAME   yourcompany.com.

• A record if the subdomain should point to a specific IP - for example, to a different server than the main domain.
• CNAME if it should follow the same target as a name you already maintain. If the IP changes there, the subdomain moves along automatically.

Important: next to a CNAME, no other record may exist for the same name. If you additionally need MX or TXT for a subdomain, use an A record. All record types are explained in DNS records explained.

The second step: the server has to play along

The DNS record only gets visitors as far as the server. What is delivered there is decided by the server itself:

• Web hosting with Plesk: create the subdomain in the subscription - its own document root, its own PHP version and its own certificate included. Details in Create a subdomain on web hosting and Connect a domain to your web hosting.
• VPS: create a separate vHost or server block for the subdomain, see Point a domain to a VPS.

If this step is missing, visitors land on the default page or the main domain.

What subdomains are worth it for

A tip for staging environments: block them via robots.txt and password protection, otherwise Google indexes your test copy and you create duplicate content.

Wildcard subdomains

A record with the name * catches all subdomains that are not explicitly defined:

*   A   85.214.12.7

This is practical for applications that assign each customer their own subdomain. But it comes at a price: typos and unrelated requests also land on your server, and a matching SSL certificate must also be a wildcard - it is issued via a DNS check instead of via HTTP.

Subdomain or subdirectory?

In terms of content, both are possible - blog.yourcompany.com or yourcompany.com/blog. The decision has less to do with SEO than is often claimed, and more to do with technology:

• Subdomain if the service should run technically separately - its own software, its own server, its own access rights.
• Subdirectory if the content belongs thematically to the main site and should benefit from its visibility.

Search engines tend to treat subdomains as independent sites. For a blog meant to strengthen the main site, the subdirectory is therefore usually the better choice - for a technically separate shop, the subdomain.

Frequently asked questions