NXDOMAIN

NXDOMAIN is a DNS response meaning that the domain name being looked up does not exist in DNS. It is an answer about the exact name that was queried, not a statement that a business, website, or domain owner does not exist in the real world.

What does NXDOMAIN tell a visitor?

If a browser looks up shop.example.com and receives NXDOMAIN, that name may have been typed incorrectly, may not have been created, or may have been removed. The parent domain example.com could still exist and work. NXDOMAIN also differs from a response that says the name exists but has no requested record type.

DNS lookup services, called resolvers, can save NXDOMAIN responses for a limited time. If a domain name was created after a negative answer was cached, some users may continue to see the cached result until it expires. A checker should therefore report the name it queried and whether its answer came from a particular resolver.

Is NXDOMAIN proof that a domain can be registered?

No. DNS and domain registration are separate systems. A registered domain may have no DNS records, and an unregistered name may be available, reserved, or subject to registry rules. Check registration data with the relevant registration service rather than relying on a DNS answer.

Related terms

• No DNS record — the name may exist but lack one record type
• SERVFAIL — resolver could not complete the lookup
• DNS — the system returning the answer
• Domain registration — separate registration status