Diagnose DNS Issues

DNS problems can be hard to spot because they often appear intermittently, or only for some visitors, resolvers, or mail providers. They are especially common after hosting moves, nameserver changes, DNS provider updates, or email platform migrations.

• Websites working for some visitors but not others
• Email being delayed, rejected, filtered, or routed incorrectly
• Old records continuing to appear after a DNS change
• SSL, verification, CDN, or provider setup checks failing unexpectedly

This checker queries the delegated authoritative nameservers directly and compares key DNS and email authentication records, helping highlight stale zones, mismatched delegation, glue issues, lame nameservers, and inconsistent SPF, DKIM, or DMARC responses.

The checker is fully functional and actively improved. Spot a bug, unclear result, or feature request? Please contact us.