What is a Subdomain and When Should You Use One?

A subdomain is the section of a domain, aka URL, that precedes the second level domain (SLD). If you are new to domain terminology, the following example should help. Take the domain ‘charity.name.com/blog/April-2026-happenings’ for instance:

• ‘charity’ is the subdomain (also known as third-level domain)
• ‘name’ is the second-level domain (SLD)
• ‘.com’ is the top-level domain (TLD)
• ‘/blog/’ is a sub folder
• ‘April-2026-happenings’ is the web page file name

To further understand what a subdomain is, understanding the ‘why’ is important. In case it is not obvious by now, name.com is a domain registrar; we sell domain names as well as related products that help you build a web presence. We are also a company that believes in donating a significant amount of time to causes and the communities where we work. Suppose we want to share information about our charitable work on our website, but we prefer to keep this information completely separate from the information about our products and services. Using a subdomain – i.e. charity.name.com – would allow us to build a whole new website using our existing domain- name.com – and hosting environment, rather than building a separate website on a new domain. Any page and subfolder you visit on charity.name.com would be specific to the charity initiatives at name.com; charity.name.com/blog/ could be a blog about our many charitable endeavors, while name.com/blog/ can remain focused on our business.

When to use a subdomain

There are many reasons to use subdomains. At the core of these reasons is a desire to create a new web experience on your existing domain. Doing so allows you to extend your existing brand to new initiatives. Here are some common reasons why an existing website may opt to use a subdomain:

• Online stores: If you run a lifestyle blog but want to start selling branded merchandise, an ecommerce platform needs different software than a blog. Putting your store at “shop.yoursite.com” keeps the complex ecommerce tools separate from your daily articles.
• Customer support portals: A dedicated help desk or frequently asked questions section often runs on specialized support software. Using “support.yoursite.com” creates a clean, dedicated space for customer service.
• International markets: If you are expanding globally, you might want different languages for different regions. You can use “es.yoursite.com” for Spanish or “fr.yoursite.com” for French, allowing you to tailor the experience to specific locations.
• Staging sites: When you want to test a new website design before launching it to the public, a staging environment like “test.yoursite.com” lets you build safely behind the scenes.

When to use subdomains vs subfolders

Subdomains allow you to create an entirely new web experience on your existing domain – new colors, font styles, layouts and brand identity – whereas subfolders will adopt the style guide in place for your main website.

How do subdomains affect SEO?

This is a major concern for many site owners when considering a subdomain. There is a lot of nuance here, too much for the scope of this article, but at a high level search engines like Google treat typically subdomains as separate websites from your primary domain (Siege Media 2025). So building out a new web experience on a subdomain will largely be starting from scratch. In some cases this is desirable. But if capitalizing on the SEO strength of your existing site, you may want to explore a strategy that employs subfolders and subdirectories.

Analytics tracking & subdomains

Because search engines treat these as separate properties, tracking your subdomain requires a few extra steps. Every analytics tool is different so consult the documentation specific to the tools you are using. Tips for some commonly used tools:

• For Google Search Console, set up a new Domain Property in order to track your subdomains and see how your entire online presence is performing in search results from a bird’s-eye view.
• For Google Analytics 4, tracking users as they move between your main site and your separate sections requires cross-domain measurement. You have to configure your tag settings to ensure that when a customer clicks from “example.com” to “shop.example.com”, they are counted as the exact same person. Otherwise, Google Analytics will record them as a brand new visitor. It takes a little technical configuration, but it is worth the effort.

Do subdomains cost extra?

Good news for budget-conscious beginners: creating subdomains does not require you to register a new domain name. When you register your primary web address through platforms like name.com, you can typically create hundreds of them for free. You simply configure them within your domain’s DNS settings. However, building out a website on a subdomain may drive up your hosting costs. The subdomain may be free, but the server resources required to host and run the added webpages are still subject to your web host’s pricing tiers.

Summary

The decision to use a subdomain over a subfolder has many implications for the site owner. From SEO to branding and analytics. And don’t just focus on your needs today. Consider how the subdomain will fit into your strategy down the road.
If you decide to move forward with a subdomain strategy, your registrar should provide very clear guidance on setting it up. If not, consider transferring your domain to name.com! We make things easy and transparent for our customers.