Wildcard SSL Certificates

Wildcard certificates provide a flexible solution for securing multiple subdomains under a single domain. A wildcard certificate for "*.example.com" secures unlimited subdomains like www.example.com, mail.example.com, and shop.example.com. This approach simplifies certificate management for organizations with numerous subdomains, eliminating the need to purchase and maintain separate certificates for each subdomain.

The economic advantages of wildcard certificates become apparent for organizations managing multiple subdomains. Instead of purchasing individual certificates for each subdomain, a single wildcard certificate covers all current and future subdomains at one level. This consolidation reduces both initial costs and ongoing management overhead. Certificate renewal becomes a single task rather than coordinating multiple expiration dates.

Wildcard certificates come with important limitations and security considerations. They only cover one level of subdomains; a certificate for "*.example.com" won't secure "sub.subdomain.example.com". From a security perspective, the compromise of a wildcard certificate's private key affects all subdomains it protects. Organizations must weigh the convenience of wildcard certificates against the increased impact of potential security breaches.

Common use cases for wildcard certificates include organizations with dynamic subdomain creation, such as software-as-a-service platforms that create customer-specific subdomains. Content delivery networks, corporate environments with numerous internal services, and multi-language websites using subdomain-based localization all benefit from wildcard certificates. The flexibility to add new subdomains without obtaining new certificates accelerates deployment and reduces administrative friction.