What Subdomain means
Subdomains suit separate systems such as apps, help centers or stores on another platform. Google can treat a subdomain more like its own site, so content meant to strengthen your main site usually belongs in a subdirectory instead.
Why it matters for your website
Subdomains are handy for running separate tools, like a help center, store or client portal, on different platforms. They may need their own setup in analytics, Search Console and security settings, so they take a bit more planning.
Example
A hypothetical gym runs its main site on one platform and its class booking system at book.example.com through a scheduling provider.
Tips
- Use subdomains for separate apps or platforms, not just to organize content.
- Add each subdomain to analytics and Search Console so nothing goes untracked.
- Remove DNS records for subdomains you no longer use.
Common mistakes
- Leaving old subdomains pointing to cancelled services, which attackers can take over.
- Splitting a small blog onto a subdomain for no clear reason.
Questions about Subdomain
What is Subdomain?
A separate host name in front of your domain, like blog.example.com.
Do subdomains need their own SSL certificate?
Each subdomain needs to be covered, either by its own certificate or a wildcard certificate. Many hosts and platforms handle this automatically.
Does Google treat a subdomain as a separate site?
Google says it can work out how subdomains relate to the main site, and either structure can rank. In Search Console, a domain property covers all subdomains together.
