Addon Domain, Subdomain and Alias: What's the Difference?

When you add a domain in cPanel you are offered three options. The wrong choice can make your second site open inside your main site, or send email somewhere unexpected. Here is when to use each.

Subdomain

Names added in front of your main domain, such as blog.example.com or shop.example.com. You don't need to buy a new domain. A subdomain runs from its own folder, so you can install an application independent of the main site.

When to use it: a test environment, a separate blog, a help centre or a campaign page.

Addon domain

Lets you host a completely different domain, for example otherbrand.com, as a separate site in the same hosting account. It gets its own folder, its own SSL certificate and, if you want, its own email addresses.

When to use it: when you want to manage several independent sites in one account. Your plan must allow more than one website; the number of sites is stated on our plans.

In recent cPanel versions, addon domains and subdomains are managed together on the Domains screen. If you leave "share document root" switched off when adding one, the domain gets its own folder, which is the right choice for a separate site.

Alias (formerly parked domain)

An alias makes another domain show your existing site exactly as it is. For example, both example.com and example.net open the same site. It has no folder of its own.

When to use it: when you have registered other extensions of your brand or common misspellings. Search engines don't like the same content appearing at two addresses, though, so it is better to 301-redirect the alias to your main domain. See the .htaccess redirect guide.

Quick decision table

Check before you add

• The domain's nameservers or A record must point to this account. Otherwise the site won't load and no SSL certificate is issued.
• If you'll use email on the addon domain, set up its MX and SPF records too. The DNS records guide helps.
• Every extra site shares the same account's CPU, RAM and inodes. For many busy sites, reseller hosting with a separate account per site is tidier.