We’ve mentioned in our articles multiple times that SSL certificates are a crucial element of website security, as they ensure data encryption between the user’s browser and the web server. However, when it comes to website security, particular attention should be paid to the use of SSL certificates for subdomains. In this article, we will explore which SSL certificates are suitable for subdomains and why this is important.

Subdomains and Their Significance

A subdomain is a part of the main domain, located in front of it and separated by a dot. For example, in the web address «», «blog» is a subdomain of the main domain «». Subdomains allow you to structure your website, organize it into separate sections, and create subdomains for ease of navigation.

When you own a website with numerous subdomains that contain important information or functionality, it’s essential that each of these subdomains is protected by an SSL certificate.

Types of SSL Certificates for Subdomains

There are various types of SSL certificates that can be used to protect subdomains. Let’s look at the most common options:

1. Wildcard SSL Certificates

Wildcard SSL certificates are designed to protect the main domain and all of its subdomains. For example, if you have a certificate for «», it will secure «», «», «», and other subdomains you specify.

2. Multi-Domain (SAN) SSL Certificates

Multi-Domain (also known as Subject Alternative Name or SAN) SSL certificates allow you to add multiple different domains and subdomains to a single certificate. You can specify a list of domains that need protection, including the main domain and all its subdomains.

3. Universal SSL Certificates

Universal SSL certificates are very convenient as they allow you to protect numerous subdomains on different domains using a single certificate. They are particularly useful for companies that manage multiple websites and subdomains.

How to Choose the Right SSL Certificate for Subdomains?

When choosing an SSL certificate for your subdomains, we recommend considering the following factors:

  • Scope of Protection. Determine how many subdomains you need to protect. If there are many, wildcard or multi-domain certificates may be the best option.
  • Budget. Check your budget and select a certificate that fits your financial capabilities.
  • Provider. Choose a reputable SSL certificate provider that offers technical support and certificate renewal options.
  • Validity Period. Take into account the certificate’s validity period and plan for its renewal in advance.

In conclusion, securing subdomains with SSL certificates is an essential component of website security. Choose a certificate that meets your needs and ensures the security of all parts of your web project.