What is a CNAME record?

A CNAME (Canonical Name) record maps one domain name to another (the canonical name). When DNS resolvers encounter a CNAME, they follow the chain to the final A or AAAA record to get an IP address.

Can I use a CNAME on a root domain?

No, RFC 1034 forbids CNAME records at the zone apex (root domain like example.com). Use an A record pointing to an IP, or use a provider that supports CNAME flattening (also called ALIAS or ANAME records).

What is the difference between a CNAME and an A record?

An A record maps a hostname directly to an IPv4 address. A CNAME maps a hostname to another hostname, which is then resolved to an IP. CNAMEs are useful for pointing multiple subdomains to the same destination without managing multiple A records.

CNAME Records

A CNAME (Canonical Name) record creates an alias from one domain name to another. The DNS lookup will continue for the destination domain.

A CNAME adds one more lookup before the address is found.

How CNAME Records Work

When a client queries a CNAME record, the DNS server responds with the canonical name and then the client must perform another lookup for that canonical name.

CNAME Record Format

blog.example.com.    CNAME    hashnode.network.
shop.example.com.    CNAME    shops.shopify.com.

When to Use CNAME

Pointing a subdomain to a third-party service (blog, shop, etc.)
Creating aliases for CDN domains
Mapping multiple hostnames to the same server

CNAME vs A Record

CNAME	A Record
Points to a domain name	Points to an IP address
Requires additional lookup	Direct resolution
Can only be used for subdomains	Can be used for any name
Cannot coexist with other records*	Can have other records

* A CNAME cannot coexist with other records at the same name (except DNSSEC)

Best Practices

Don't use CNAME at the root domain (example.com) for your main website
Ensure the target domain always resolves
Test with our CNAME Lookup tool

Try it on your domain

See the theory in practice — run a CNAME Lookup for your own domain.