Domains and hostnames

A Site hostname is configuration, not the permanent Site identity. Changing the primary hostname keeps the same Site, storage, runtime, applications and Site-owned resources.

Change the primary domain

Open Site Settings → Site Identity → Change Domain. Control checks that the requested hostname is not already owned by another Site before promoting it.

You can keep the previous primary hostname attached as an alias during the transition or remove it when it should stop being served.

TLS-safe promotion

The new hostname must have valid certificate coverage before HTTPS can be considered ready. For managed Let's Encrypt certificates, make sure public DNS points to the server. Imported/shared certificates must already cover the new hostname.

DNS and application configuration are separate

Changing the Site primary hostname does not silently edit external DNS, Mail Domains, Cloudflare publications or application-level canonical URLs. Update those independent resources where required.

Cloudflare Tunnel

If this Host has a connected Cloudflare Tunnel, publish or unpublish Site hostnames through the Site/Connectivity workflow. Tunnel publication is separate from renaming the Site.

Micro CMS external Silo domains

A Micro CMS Site using Dedicated IP · catch-all ingress has a separate provider-domain path. Register the Silo hostname in Micro CMS and point that exact hostname's DNS to the dedicated Control address; do not also attach the same Silo hostname as an ordinary Site alias.