What is a wildcard certificate?

  General Questions

A Wildcard SSL certificate is used to secure unlimited sub-domains within the same level that share a common base domain.

For example: A Wildcard certificate issued to *.mydomain.com can be used to secure the following domains:

  • login.mydomain.com
  • secure.mydomain.com
  • support.mydomain.com
  • www.mydomain.com etc.

Along with multiple subdomains, a Wildcard SSL will also secure the bare domain mydomain.com.

Comodo (now Sectigo) certificates issued for *.sub.mydomain.com will also secure sub.mydomain.com.