A CNAME record, short for canonical name, makes one domain name an alias of another. Instead of pointing to an address, it says “this name is the same as that name,” and anyone looking it up follows the alias to find the real address.
How a CNAME Record Works
If www.example.com has a CNAME pointing to example.com, a lookup for www.example.com first returns that alias, then looks up example.com to get its address. If the address of example.com ever changes, the www name follows automatically, because it never stored an address of its own.
Common Uses
CNAME records are used to point a www name at the main domain, to connect a subdomain to an outside service, such as a store, a help desk or an email marketing tool, and to verify domain ownership for some services. Many hosted platforms ask you to add a CNAME rather than an address, so they can move their servers without you changing anything.
Rules and Pitfalls
A name with a CNAME record cannot have any other records, so the main domain itself, the bare example.com, cannot normally be a CNAME. Some DNS hosts offer a workaround, often called flattening or an ALIAS record. Another common problem is a dangling CNAME, an alias that still points to a service you no longer use, which someone else could sometimes claim.
The Domibot CNAME Lookup follows an alias to its final address and flags dangling records.