CNAME flattening speeds up
CNAME resolution and allows you to use a
CNAME record at your root/apex domain (
How it works
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
CNAMEflattening happens by default in some cases, as explained in its Setup page
- If a
CNAMEtarget 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 the
CNAMErecord itself will not be returned directly.