Wildcard SSL vs. Multi-Domain SSL: Key Differences and Best Use Cases

As businesses expand their online presence, securing multiple domains and subdomains becomes increasingly important. SSL (Secure Sockets Layer) certificates, which encrypt data to protect users and sites, are essential for maintaining website security. However, with various types of SSL certificates available, it can be challenging to determine which one best suits a specific organization’s needs. Two common types for businesses managing multiple sites or subdomains are Wildcard SSL and Multi-Domain SSL certificates. While both serve the purpose of securing multiple parts of a business's online infrastructure, they do so in different ways. This article explores the key differences, advantages, and ideal use cases for Wildcard SSL and Multi-Domain SSL certificates.

What is a Wildcard SSL Certificate?

A Wildcard SSL certificate is designed to secure a domain and all of its subdomains under a single certificate. The main feature of this type of certificate is that it includes a wildcard character (represented by an asterisk *) before the domain name, which allows it to protect an unlimited number of subdomains. For example, if you purchase a Wildcard SSL for *.example.com, it will secure example.com, blog.example.com, shop.example.com, and any other subdomains under that main domain.

Key Features of Wildcard SSL Certificates:

Secures unlimited subdomains: A Wildcard SSL can secure a limitless number of subdomains without needing separate certificates for each one. This is particularly beneficial for businesses that regularly add new subdomains, such as blogs, stores, or support pages.

Cost-effective for subdomain-heavy websites: If an organization manages numerous subdomains, the cost savings of a single Wildcard certificate compared to purchasing multiple individual certificates are significant.

Simplifies management: Instead of juggling numerous SSL certificates for different subdomains, you manage everything under one Wildcard SSL, reducing administrative effort.

However, Wildcard SSL certificates have some limitations. Most notably, they only secure subdomains at a single level. If your organization uses second-level subdomains (e.g., store.eu.example.com), a standard Wildcard SSL will not cover them. Additionally, Wildcard certificates cannot secure multiple top-level domains (TLDs) such as example.com and example.net.

What is a Multi-Domain SSL Certificate?

A Multi-Domain SSL certificate, also known as a SAN (Subject Alternative Name) SSL, is designed to secure multiple domains and, in some cases, their subdomains. This type of certificate allows businesses to protect various distinct domain names under one SSL certificate. For instance, a single Multi-Domain SSL could secure example.com, example.net, and mywebsite.org.

Key Features of Multi-Domain SSL Certificates:

Secures multiple domains: Multi-Domain SSLs are ideal for businesses with more than one domain or brand. You can secure different domains and, in many cases, subdomains across those domains without purchasing a separate certificate for each.

Customizable domain list: With Multi-Domain SSL certificates, you can customize the list of domains and subdomains you wish to secure. It provides flexibility in adding or removing domains as your business grows or changes.

Unified certificate management: Instead of managing separate certificates for each domain, Multi-Domain SSLs allow for consolidated management. This can simplify renewals, installations, and other SSL-related administrative tasks.

However, Multi-Domain SSL certificates are typically limited in the number of domains they can cover. While the exact number varies depending on the certificate provider, common limits are around 100 domains, with options to purchase more at an additional cost. Additionally, they may not offer as much flexibility as Wildcard SSL certificates when dealing with subdomains, as each domain must be explicitly listed.

Wildcard SSL vs. Multi-Domain SSL: Core Differences

Number of Domains vs. Subdomains: The primary distinction lies in what each certificate secures. A Wildcard SSL protects one domain and all its subdomains, while a Multi-Domain SSL secures multiple domains, with optional coverage for subdomains.

Scope of Security: Wildcard SSLs are best suited for organizations focused on a single domain but with many subdomains, such as shop.example.com, blog.example.com, etc. Multi-Domain SSLs, on the other hand, are optimal for businesses that manage different brands or websites across multiple domains like example.com and example.net.

Certificate Management: Wildcard SSL certificates offer streamlined management of subdomains within a single domain. Multi-Domain SSLs consolidate certificate management across several domains, making them more suitable for organizations with a diverse domain portfolio.

Cost Considerations: The cost-effectiveness of each certificate type depends on your business’s structure. If you operate under one domain with numerous subdomains, a Wildcard SSL certificate offers significant savings. However, if you manage multiple domains, a Multi-Domain SSL might be more economical since purchasing individual SSL certificates for each domain could be cost-prohibitive.

Flexibility: Wildcard SSLs provide flexibility for adding subdomains without changing the certificate. Multi-Domain SSLs allow more flexibility across multiple domains but may require updates as you add or remove domains from the certificate.

Best Use Cases

Wildcard SSL Certificate: This is ideal for businesses with one main domain and numerous subdomains. A blog network, e-commerce platform with multiple sub-stores, or SaaS platforms using subdomains for different clients can benefit from the simplicity and cost savings of a Wildcard SSL.

Multi-Domain SSL Certificate: This certificate is suitable for businesses with multiple domains, such as companies managing different brands, franchises, or regional websites. It’s also a good fit for organizations needing to secure both domain and subdomain combinations like example.com and store.example.com, alongside distinct domains such as example.org.

Conclusion

When deciding between a Wildcard SSL and a Multi-Domain SSL certificate, understanding your business's domain structure is key. If your focus is on securing one domain and its subdomains, a Wildcard SSL will provide a flexible, cost-effective solution. However, if your business spans multiple domains and brands, a Multi-Domain SSL offers the convenience of securing everything under a single certificate, making it an optimal choice for diverse online operations. Ultimately, both certificates are powerful tools for enhancing website security, but selecting the right one depends on your organization’s specific needs.