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
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 theCNAMErecord itself will not be returned directly.