What Is a CNAME Record in DNS?

TL;DR
A CNAME record (Canonical Name) creates an alias, it points one domain name to another domain name (not directly to an IP).
DNS resolvers follow the CNAME to the target domain and resolve its A or AAAA record.
This is ideal for subdomains (e.g. www → root domain, or CDN endpoints), but cannot be used at the root domain if other records (MX, TXT, etc.) exist.

Look up CNAME records

Enter a domain name to lookup CNAME records

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How CNAME Records Work

When a resolver sees a CNAME:

It stops looking for other records at that name.
It queries the target domain instead.
It continues until it finds an A/AAAA record (or another CNAME, but avoid long chains).

CNAMEs are great when the target IP might change (e.g. CDN, hosted service), update the target's A record once, and all aliases follow.

Common Use Cases

www alias: www.example.com → example.com
CDN integration: cdn.example.com → CloudFront / Akamai endpoint
Third-party services: blog.example.com → WordPress.com, GitHub Pages, etc.
Subdomain redirects: Alias subdomains to different providers without duplicating IPs
Easier migrations: Change one target instead of many A records

How to Lookup CNAME Records

dig www.example.com CNAME

nslookup -type=CNAME www.example.com

Record Format

NAME                TTL    CLASS  TYPE   VALUE
www.example.com.    3600   IN     CNAME  example.com.

VALUE: Must be another domain name (FQDN with trailing dot recommended)
Only one CNAME per name allowed
No other records (A, MX, TXT, etc.) can exist at the same name

Valid Examples

Classic www alias

www.example.com.  CNAME  example.com.
example.com.      A      192.0.2.1

CDN example

cdn.example.com.  CNAME  d1234567890.cloudfront.net.

GitHub Pages / hosted service

blog.example.com.  CNAME  username.github.io.

Multiple subdomains

api.example.com.   CNAME  api.backend-service.net.
shop.example.com.  CNAME  shops.myshopify.com.

CNAME vs A / AAAA Records

Feature	CNAME	A / AAAA
Points to	Domain name	IP address
Extra DNS lookup	Yes (adds latency)	No
Allowed at root	No (if other records exist)	Yes
Multiple per name	No (only one CNAME)	Yes
Other records allowed	No	Yes
Best for	Changing targets (CDN, hosting)	Static/performance-critical

→ See also: A Record, AAAA Record

Frequently Asked Questions

Can I use CNAME at the root domain (example.com)?

No, not if you have MX, TXT, NS, or other records. Use A/AAAA instead. Some providers offer "CNAME flattening" / ALIAS records as a workaround.

Can a CNAME point to another CNAME?

Yes, but avoid it, chains increase latency and failure points.

What's better: CNAME or A record?

Use A/AAAA for speed and root domains.
Use CNAME for flexibility when the target might change (CDN, SaaS).

Can I have CNAME and other records at the same name?

No, DNS forbids it. If a CNAME exists, no other types (A, MX, etc.) can coexist at that exact name.

References

RFC 1035

Domain Names - Implementation and Specification

Related: A Record · AAAA Record · DNS Basics