Why the apex and www can return different answers

Check both entry points, and distinguish a DNS alias from a web redirect.

Query each entry point

example.com and www.example.com are separate DNS names. One working correctly does not establish that the other is configured. During a migration, include all entry points that visitors actually use in your checklist.

An alias is not a redirect

CNAME expresses an alias at the DNS layer. It does not change the address displayed in a browser. Consolidating www and the apex generally also requires an HTTP redirect configured in the web server, CDN or hosting platform.

Follow the hosting platform’s model

The apex normally also has records such as NS and SOA, so its configuration cannot simply copy a www CNAME. Some providers offer ALIAS or flattening features whose public answers appear as A or AAAA records. Follow the instructions for your current provider.

This guide explains public DNS responses. Before changing production settings, check the documentation for your current domain and hosting providers.