Free nameserver lookup. Enter a domain and see its delegated NS records, the authoritative nameservers, each resolved to its own IPv4 and IPv6 address. Resolved live from our London probe. The quick way to confirm a domain's nameservers, spot a delegation still pointing at an old or dead host, and verify a DNS provider migration went through.
A domain's NS records name the authoritative nameservers, the servers that hold the real DNS answers for that domain. When you change your nameservers at the registrar, you are handing control of the domain's DNS to a different provider, which is exactly what happens when you move a domain to Cloudflare, Route 53, or a new host. This tool lists the delegated nameservers and, unlike a plain lookup, resolves each one to its own IP so you can confirm they are real and reachable.
After you update nameservers, the change has to propagate from the registry down to resolvers, which can take up to 48 hours depending on the parent TTL. If a delegation still lists an old or decommissioned nameserver, DNS answers can be inconsistent or fail intermittently. Looking up the live NS set is the fastest way to confirm a migration actually took effect and that no stale server was left behind.
A nameserver is an authoritative DNS server that holds the records for a domain and answers queries about it. A domain's NS records delegate it to these servers.
Enter the domain in the tool above. It returns the delegated NS records and resolves each nameserver to its IPv4 and IPv6 address.
Redundancy. If one nameserver is unreachable, resolvers can still get answers from another. Most registrars require at least two nameservers for exactly this reason.
Usually a few hours, but up to 48 hours in the worst case. The delay is bounded by the TTL that the registry publishes on the parent delegation, not by your own zone's TTLs.
