A wildcard SSL certificate is a type of SSL that secures a website and all its subdomains using a single certificate. Instead of getting individual security certificates for each part – like one for your main page, another for your blog, and yet another for your online shop – a wildcard SSL covers them all with just one.

It’s called “wildcard” because it uses an asterisk * to stand in for any subdomain, such as *.example.com. This is especially useful for businesses that run multiple subdomains but want to simplify security and save on costs.

How wildcard SSL works

Just like a regular SSL certificate, a wildcard SSL encrypts the connection between your visitors' browsers and your website. This keeps any information they share safe and sound. The key difference is its wider reach.

• Single certificate, multiple subdomains. You only need to install and manage a single certificate to secure all your initial subdomains.
• Wildcard character support. That little * is what allows the certificate to work across various subdomains.
• Domain validation. Most wildcard SSLs use domain validation (DV), which means the certificate provider checks that you actually own the main domain.

Because most web browsers and devices understand and trust these certificates, a wildcard SSL is a pretty versatile option for today's websites.

When to use a wildcard SSL

Consider going for a wildcard SSL if:

• You currently have multiple subdomains or plan to add them in the future.
• You'd prefer the simplicity of managing just one SSL certificate instead of several.
• You're looking for a more cost-effective way to secure a website with a growing number of sub-sections.

Let’s say you run an online business with separate sections for customers, staff, and support. For instance: customers.example.com, team.example.com, and support.example.com. With a wildcard SSL, you can secure all of these without juggling individual certs.

Limitations of wildcard SSLs

While they offer great convenience, there are a couple of things to keep in mind.

• Wildcard SSLs only cover the first level of subdomains. (e.g., *.example.com but not *.*.example.com).
• You typically won't find wildcard SSLs with Extended Validation (EV) or Organization Validation (OV), which offer a more rigorous identity check.
• If the single private key for your wildcard SSL is compromised, all your subdomains become vulnerable. So, keeping that key safe is extra important.

If you handle really sensitive information on some parts of your site (like payment pages or user accounts), you might want to consider separate, higher-validation certificates for those specific areas for an extra layer of security.

FAQs about wildcard SSL

Why use a wildcard SSL instead of a regular SSL?

It's all about efficiency and cost if you have multiple subdomains. One wildcard certificate is easier to manage and often cheaper than buying several individual SSLs.

Is a wildcard SSL safe?

Absolutely. They provide the same strong encryption as regular SSL certificates and are trusted by all major browsers. Just remember that securing the private key is paramount.

Do wildcard SSLs work with www and non-www?

Yes. If you get a wildcard for *.example.com, it will cover www.example.com, but not example.com itself. You’ll need to add that separately or choose a certificate that includes both.

Can I use a wildcard SSL for sub-subdomains?

Nope. Wildcard SSLs only protect one level of subdomains.

Keep your site secure with B12

B12 takes care of your website setup for you. Our platform helps ensure your entire online presence is secure, so you can focus on growing your business. Launch your secure website with B12 today!