Hostnames and domains are the backbone of the internet’s domain name system (DNS). And while your root domain anchors your primary site, subdomains have become a practical way to spin up focused experiences—without buying a brand-new domain.
Think of a subdomain as a child of your parent domain: separate enough to run its own software, design, or navigation, but still clearly connected to the brand that owns the main site.
For example, your main site might live at duolingo.com while your blog runs at blog.duolingo.com. In a URL, the subdomain sits to the left of the root domain in the full hostname (FQDN).
Subdomains can be used strategically by operations, marketing, and support teams to organize complex websites into clear, user-relevant sections.
For instance, nytimes.com uses a subdomain to host a dedicated cooking experience for readers.
What Is a Subdomain Name?
In simple terms, a subdomain name is the label you add in front of your root domain to create a distinct section of your site—like blog.example.com or support.example.com.
A domain is the human-readable address people type to reach your site (e.g., Google at google.com or Quick Sprout at quicksprout.com). You register that name through a domain registrar. The full hostname (also called an FQDN) can include one or more subdomains before the root domain.
When someone navigates to your site, DNS looks up the domain, translates it to the correct IP address, and routes the request to your hosting server.
Alright, back to subdomains.
A subdomain lets you extend your site in an organized, user-friendly way. Instead of registering a separate domain, you create a subdomain under the domain you already own to run a related—but purpose-built—experience.
Example: in cloud.google.com, the label cloud is the subdomain, and google.com is the primary domain.
On the technical side, a subdomain is simply a DNS label for which you add records (commonly A/AAAA or CNAME). An A/AAAA record points the subdomain to a specific server IP; a CNAME points it to another hostname. You can also delegate a subdomain to different name servers with NS records if needed.
Practically, creating a subdomain means adding the appropriate DNS record(s) for that label in your zone file. Most web hosts automate this when you create a subdomain in your control panel.
What subdomains allow website owners to do
While the root domain anchors the main site, subdomains help you launch clearly separated sections with their own content, software stack, or team—without confusing users or overcomplicating your main navigation.
They’re also useful when different areas of your site need different tech, security boundaries, or infrastructure (for example, a SaaS app on one stack and a marketing site on another).
Subdomains can also localize experiences for different countries or regions, which is helpful for brands serving large, globally distributed audiences.
Common ways to use subdomains include:
- Blogs and editorial hubs
- Shopping, ecommerce, and online stores
- Customer and technical support portals
- Internationalization and localization (e.g., fr.example.com)
- Separate mobile sites (legacy approach; most sites now prefer responsive design)
- Job boards and careers
- Web apps, dashboards, and account areas (e.g., app.example.com)
- Developer docs and APIs (e.g., developers.example.com, api.example.com)
- Community forums, knowledge bases, or status pages
Google is a well-known example of thoughtful subdomain use. Beyond Search, you’ll find services living at:
- play.google.com
- book.google.com
- maps.google.com
- support.google.com
- developers.google.com
- docs.google.com
- drive.google.com
- sites.google.com
- apis.google.com
- mail.google.com
- calendar.google.com
- translate.google.com
- earth.google.com
- fi.google.com
The difference between subdomains and subdirectories
People often conflate subdomains and subdirectories because both organize content but at different layers.
Subdirectories are folders on the same host, represented as a path at the end of the URL (e.g., /blog/). They’re great for grouping content by topic while keeping everything under the same site structure and analytics.
For example, yourdomain.com/blog/ keeps all blog content in one logical area, which tends to be simpler for users, internal linking, and centralized management.
Subdomains sit before the root domain (e.g., blog.yourdomain.com) and are often used when the content, software, or audience is distinct enough to benefit from separation—like a SaaS app, developer docs, or country sites.
From a search perspective, Google can crawl and rank both models effectively. In practice, subdomains often behave like separate properties—you’ll typically verify them individually in Search Console, manage their sitemaps and robots settings, and build internal links so signals flow between sections.
As a quick way to reason about the choice:
- Use subdirectories when content is tightly related to the main site and you want to consolidate authority, backlinks, and analytics with less overhead.
- Use subdomains when you need technical isolation, different software or teams, clear audience separation, or region-specific experiences.
Subdomains don’t inherently “compete” against your main site. Fragmentation usually happens when content is duplicated or internal linking is weak. If consolidation is your goal, a subdirectory is typically simpler. If separation is your goal, a subdomain can be the cleaner long-term choice.
Why Use Subdomains?
Teams use subdomains because they unlock flexibility without sacrificing brand clarity. Benefits include:
- Internationalization: Serve different languages or countries via distinct sites (e.g., en.example.com, de.example.com) while tailoring content and legal notices.
- Site performance & reliability: Split a sprawling monolith into services that can scale independently and be maintained by different teams.
- Separate SERP footprints: Subdomains can build their own site-level signals and may appear alongside the main site, increasing overall visibility when content is distinct and valuable.
- Branding: Give special initiatives (events, communities, academies) room for their own design and messaging while keeping brand trust.
- Niche authority: Concentrate deep, specialized content (e.g., developer docs) to grow topical expertise without diluting your main navigation.
- Operational independence: Use different tech stacks, deployments, and access controls where needed.
- Cleaner information architecture: Reduce complexity on content-heavy sites by grouping large, distinct sections at the subdomain level.
When a subdirectory might be better
Choose a subdirectory if the content is editorially related to the core site, you want the simplest SEO setup, and you don’t need separate infrastructure. It keeps link equity and analytics centralized and usually requires less maintenance.
How to Create a New Subdomain
Exactly how you create a subdomain depends on your host, but many of the top web hosting platforms follow a similar process.
1. Open cPanel. The graphical interface includes tools for domains, files, databases, and more.
2. Go to Domains > Subdomains. Inside the Domains panel, choose the Subdomains option.
3. Enter subdomain details. Specify the subdomain label (e.g., blog), select the parent domain (hostname), and confirm the document root—the folder where this subdomain’s files will live.
4. Create DNS records (if your host didn’t do it automatically). Most hosts add DNS for you when you create a subdomain. If not, open your DNS manager (sometimes labeled Advanced DNS) and add the record. Use an A or AAAA record to point the subdomain to a server IP, or a CNAME to point it to another hostname. Provide the type, host (the subdomain label), value (IP or target hostname), and TTL, then save.
Propagation tip: DNS updates can take minutes to a few hours to be visible worldwide (occasionally up to 24–48 hours, depending on TTLs and caching).
5. Secure it with HTTPS. Ensure your TLS/SSL certificate covers the new subdomain (via a SAN certificate or a wildcard like *.example.com). Many hosts issue/renew certificates automatically; if not, provision one before launch.
6. Connect analytics and search tools. If the subdomain serves unique content, verify it as a separate property in Google Search Console, submit its sitemap, and confirm analytics tracking.
7. Harden and integrate. Add internal links from your main site, set appropriate robots rules, and use canonical tags to avoid accidental duplication across subdomains and subdirectories.