Apex domain
In one line
An apex domain is your domain name with nothing in front of it, such as example.com rather than www.example.com. It is also called the root, bare or naked domain, and it follows stricter DNS rules than a subdomain.
Root, bare, naked: one idea
Take www.example.com and remove the www. What is left, example.com, is the apex. People call it the root domain, the bare domain or the naked domain, and they all mean the same thing: the top of the name you registered, the part you pay for each year.
Everything else, such as www, blog or shop, is a subdomain that sits under the apex.
A quick way to find the apex: read the address from the right. Take the ending, such as .com or .co.uk, plus the one word just before it. That pair is what a registrar sells you. Anything further to the left is yours to create.
Why the apex is special
The apex carries records that keep the whole domain working. It holds the nameserver records that say who answers for your domain, and often mail records too. Because of that, the DNS standard does not let you put a CNAME on the apex: a CNAME must be the only record on its name, and the apex can never be alone.
So the apex is usually pointed with A records, which hold an IP address. Some DNS hosts offer an extra record type, often called ALIAS, ANAME or CNAME flattening, that lets the apex follow a host name like a CNAME would. Whether yours offers it depends on the DNS host, not the registrar's brand.
Should visitors use the apex or www?
Either works. Short addresses read nicely on a business card, so many people make the apex their main address and redirect www to it. Others prefer www because it can use a CNAME. What matters is choosing one and sending the other to it, which our www or non-www entry covers.
Pointing your apex at Mini Casa
The custom domain guide explains the apex route and the www route. Custom domains are in preview, so the exact records appear in your dashboard when domain connection is available for your account. Until then you can share your free Mini Casa address, and you can see what custom domains will do. To see what your apex points at today, try the DNS checker.
Questions people ask
Is the apex the same as the root domain?
Yes. Apex, root, bare and naked domain all describe the registered name with nothing in front of it, such as example.com. Different hosts simply use different words for it.
Why won't my DNS host let me put a CNAME on the apex?
Because the apex must hold nameserver records, and a CNAME has to be the only record on its name. Use the A records your host gives you, or an ALIAS record if your DNS host offers one.