What is a CNAME record?
Reviewed by Prabath Thalangama · Last updated
A CNAME record makes one name an alias of another, so www.example.com can point at example.net and follow whatever addresses that name has. This lookup shows the alias target for the exact name you enter, which is how you confirm a CDN, SaaS or verification CNAME is in place.
A CNAME applies to the whole name: no other record type may exist alongside it, which is why the apex domain can't be a CNAME. Resolvers follow the chain to the final A or AAAA records.
A CNAME left pointing at a deleted cloud resource is a subdomain takeover risk; the takeover checker looks for exactly that.
How do I check a CNAME record?
- Enter the full name of the alias, for example www.example.com or the verification name a provider gave you.
- Compare the target with the value the provider asked for.
How to read the results
- value
- The canonical name the alias points to, without the trailing dot.
- No CNAME records found
- The name is not an alias. It may still have A or other records of its own.
Common CNAME problems
Provider says the CNAME is missing
The DNS panel appended your domain twice, creating name.example.com.example.com. Enter only the host part in panels that add the domain automatically.
CNAME and other data error
A name with a CNAME can't also have MX, TXT or A records. Move the other records to a different name or replace the CNAME with A records.
Dangling CNAME
The target no longer exists (a deleted app or bucket). Remove the CNAME or recreate the resource before someone else claims it.
Examples and command-line equivalents
Look up a CNAME
dig +short CNAME www.example.com
dig +trace www.example.com # follow the full chainCNAME in a BIND zone file
www.example.com. 3600 IN CNAME example-site.cdnprovider.net.Frequently asked questions
Can a CNAME point to another CNAME?
Yes, resolvers follow chains, but each hop adds a lookup. Keep chains short; some resolvers give up after a handful of hops.
CNAME or A record for a subdomain?
Use a CNAME when the target's addresses are managed by someone else, such as a CDN or SaaS provider, so changes follow automatically. Use A records when you control the IP addresses.
Further reading
- DNS Resolution, Step by Step
- Route 53 Routing Policies, Explained
- RFC 1034: Domain Names, Concepts and Facilities
- RFC 2181: Clarifications to the DNS Specification
- Run a full Super Scan to check DNS, email, website and TLS for a domain at once.