What is a subdomain?

All website URLs consist of the trans­mis­sion protocol (HTTP or HTTPS), a second-level domain, and a top-level domain. For example: example.org – “example” is the second-level domain (the domain name), while “org” at the end rep­re­sents the top-level domain. In addition to these essential com­po­nents, a URL can also contain a subdomain. But what is a subdomain?

Subdomain explained in detail

A subdomain allows you to divide your website into separate sections. The subdomain name appears before the domain name and the top-level domain, separated by a dot. The following image il­lus­trates this:

Close

In this example, “photos” is the subdomain of the main domain “example.” This allows a website owner to create a stand­alone section, such as one featuring photos from various events, and separate it from other content on the site.

Why use sub­do­mains?

Now that we’ve answered the question “what is a subdomain?”, the next question is: why should you create a subdomain? The primary purpose of a subdomain is to separate different areas of a website and structure the content more ef­fec­tive­ly. Because all sections share the same domain name, users can clearly see that they belong to the same company, product, or project. This not only improves user-friend­li­ness but also helps highlight specific topics or services.

Sub­do­mains are par­tic­u­lar­ly useful for large busi­ness­es with multiple locations. If each location has unique re­spon­si­bil­i­ties and in­for­ma­tion that the company wants to present on the website, it makes sense to create a separate subdomain for each one. This allows companies to provide targeted in­for­ma­tion for each location via its own subdomain.

Other practical uses for sub­do­mains include:

• Multiple languages: It’s common to separate different language versions of a website using sub­do­mains. For example, the English version might be at en.example.org, while the Spanish version is available at es.example.org.
• Customer and partner areas: Sub­do­mains like customers.example.org or partners.example.org can offer secure areas for specific user groups. These might include invoices, offers, or doc­u­men­ta­tion – often ac­ces­si­ble only with a login.
• Landing pages: Marketers use landing pages to attract potential customers. These pages are tailored to specific offers and optimized to convert visitors into customers. To avoid clut­ter­ing the main site hierarchy, landing pages are often hosted on a subdomain. This maintains the company as­so­ci­a­tion while allowing the marketing team flex­i­bil­i­ty in layout and design.
• Technical services: Sub­do­mains are also useful for technical services such as email (imap.example.org) or FTP servers (ftp.example.org).

How to create a subdomain

You must have a main domain in order to create a subdomain. Once you own or have reg­is­tered a domain, you can create sub­do­mains using a DNS entry. To do this, simply create a DNS record with the desired subdomain name and point it to the server that will host the subdomain. Sub­do­mains are created via the provider that manages your domain’s DNS settings. In most cases, this is your web host, though it could also be your domain registrar depending on your setup.

Web hosting providers make it easier to create sub­do­mains with built-in tools, so you don’t always have to create DNS records manually. Often, entering a name is all it takes – the provider handles the rest. The setup process can vary depending on the hosting provider.

If you’re thinking about creating a subdomain, keep in mind the option of a wildcard subdomain. This type of subdomain allows you to redirect all requests to undefined sub­do­mains to a specific page, helping you avoid error messages.

SEO relevance of sub­do­mains

When expanding a website, website owners often wonder whether to use sub­do­mains, di­rec­to­ries, or new domains. So how do sub­do­mains impact SEO?

Sub­do­mains are con­sid­ered separate domains by search engines and are not au­to­mat­i­cal­ly linked to the root domain. As a result, the main domain doesn’t transfer link power or trust to its sub­do­mains. This means that each subdomain needs to be optimized in­di­vid­u­al­ly for keywords and requires its own link-building strategy. One advantage is that if a subdomain is penalized by Google’s algorithm, the main domain and other sub­do­mains aren’t affected. The reverse is also true: despite being treated as separate domains, sub­do­mains can have a positive impact on overall brand presence when supported by strong internal linking and clear thematic structure.

Ad­di­tion­al­ly, search engines typically display only one result per domain in search results. By using sub­do­mains, you can place multiple listings, thereby in­creas­ing your click-through potential.