Before launching a site, DNS needs a final check. Small mistakes can make the website work while email, verification, or subdomains fail.
Website Records
Check the root domain and www. Make sure both point where you expect.
Query the authoritative nameservers and compare the returned A, AAAA or CNAME values with the new host. An old AAAA record can send IPv6 visitors to the previous server even when the A record is correct. Decide whether www redirects to the root domain or the root redirects to www, then test the chosen version over HTTPS.
Email Records
Confirm MX, SPF, DKIM, and DMARC records before changing nameservers.
Copy the complete records, including priorities and long DKIM values. Check whether the domain also uses Microsoft 365, Google Workspace, a newsletter service or a transactional mail provider. SPF must remain a single record; combine authorised senders instead of publishing several SPF TXT records. Send a message in both directions after the change.
Verification Records
Keep TXT and CNAME records used by search consoles, payment providers, CRMs, and mailing platforms.
These records are easy to overlook because they do not affect the visible website. Export the old DNS zone and compare it line by line with the new zone. Keep ownership checks for Google Search Console, Microsoft services, payment gateways and certificate authorities unless you have confirmed they are obsolete.
Subdomains
Check staging, shop, portal, app, mail, and other subdomains before going live.
List subdomains from the existing DNS zone rather than relying on memory. Some may point to third-party services and should not move with the main website. Remove abandoned staging records if they expose an old application, but verify ownership before deleting anything.
Lower TTL and Verify the Change
Lower the relevant TTL at least one existing TTL period before launch where your provider permits it. After switching, check several public resolvers, load the site from another network and inspect the certificate. Leave the old hosting available until the website, email, forms and scheduled integrations have all been tested.
A DNS checklist prevents the classic launch problem where the website works but everything around it breaks.
