A subdomain such as portal.example.com can host a separate application under a domain you control. It normally needs its own document root, DNS destination and TLS coverage. Creating it does not require registering another second-level domain.
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Check access and requirements
Confirm the parent domain is in the subscription and that its plan permits another subdomain. Decide the application location and access policy. A staging subdomain should not expose private test data or send real customer messages unintentionally.
01 Create a subdomain website in Plesk
- Open Websites & Domains and choose Add Subdomain.
- Enter the subdomain label and select the correct parent domain. Review the full hostname before proceeding.
- Choose a dedicated document root. Do not point it at the live site directory unless sharing the same content is intentional and the application supports both hostnames.
- Create the subdomain, then upload or deploy its application. Configure any database and application base URL separately.
- Check the authoritative DNS. If DNS is managed elsewhere, add the appropriate record there. Issue or select a valid certificate covering the new hostname, and configure HTTPS.
How do I verify the new subdomain website?
Resolve the full hostname and test its HTTPS page. Confirm it serves the intended content without interfering with the parent website. Test authentication, scheduled tasks and outgoing messages if this is an application environment.
Resolve setup problems
If a default page appears, compare DNS, document root and the expected index file. If certificate validation fails, check the hostname records and validation method. Do not remove the parent domain to fix a subdomain issue. For a private staging site, restrict access through an appropriate authentication or network control rather than relying on an obscure name.