CNAME flattening was popularized in part by Cloudflare.
We have used CNAME flattening successfully for years with multiple web-hosting providers.
DNS A records are a pre-WWW artifact necessary to resolve the apex domain
Implement CNAME flattening
To enable CNAME flattening with your DNS records, first screenshot or otherwise backup your DNS settings. Don’t do this experiment during busy times, better to use on a little-used or test website first to ensure it works correctly with your complete setup.
- Determine the web address your web hosting provider puts your website at. E.g. for GitHub Pages it would be
username.github.ioor at Netlify
- Remove DNS
example.invalidthat points to a specific IP address
- Add a
example.invalidto the server address from step #1
For GitHub username
joe with GitHub Pages site at
joe.github.io, with desired web address
example.invalid: make a
CNAME DNS record with
example.invalid as an alias to
Again, you do NOT need
AAAA DNS records when using
- Cloudflare CNAME flattening article
- You may see some old 2014 blog posts initially complaining about CNAME flattening, but these initial hiccups have been resolved long ago.