Following this method will guarantee the speed and reliability of your domain since Vercel will handle the subdomain.
CNAME flattening is a supported feature, however, it will impact the
performance of your root domain. We recommend users to redirect the root
domain (example.com) to the
(www.example.com) when possible.
If your domain does require the Cloudflare's proxy to be turned on by default, only one requirement is needed:
- The domain must allow HTTP requests (without HTTPS) to the path
To verify if that is possible with your domain, you can run the following command (notice the
http:// part in the URL):
curl http://example.com/.well-known/acme-challenge -I
A configuration that does allow Vercel to run smoothly would return the following:
curl http://example.com/.well-known/acme-challenge -I HTTP/1.1 404 Not Found
If you run the
curl command and receive a
3XX redirect instead, Cloudflare is preventing this route from being accessed, and Vercel will mark the domain as not configured:
curl http://example.com/.well-known/acme-challenge -I HTTP/1.1 404 Moved Permanently
You need to explore the following configuration in the Cloudflare dashboard:
Vercel cannot offer Cloudflare-specific support. If you are facing difficulties with your Cloudflare managed domain, please reach out to their support at https://support.cloudflare.com.