CNAME flattening
CNAME
flattening speeds up CNAME
resolution and allows you to use a CNAME
record at your root/apex domain (example.com
).
How it works
With CNAME
flattening, Cloudflare finds the IP address that a CNAME
points to. This process could involve a single lookup or multiple (if your CNAME
points to another CNAME
). Cloudflare then returns the final IP address instead of a CNAME
record, helping DNS queries resolve up to 30% faster.
For more details on the mechanics of CNAME
flattening, review the CNAME flattening diagram and refer to the Cloudflare blog post.
Aspects to keep in mind
CNAME
flattening happens by default in some cases, as explained in its Setup page- If a
CNAME
target is being used to verify a domain for a third-party service, enabling the Flatten all CNAMEs setting may cause that functionality to work incorrectly since theCNAME
record itself will not be returned directly.