DNS Tool
NS Lookup (Nameserver Checker)
Lookup NS records to find the authoritative nameservers for a domain. Validate DNS provider cutovers and troubleshoot authority issues fast.
Purpose
Find authoritative DNS
Confirm which nameservers answer for your domain.
Best For
DNS migrations
Avoid mismatched zones during cutovers.
Tip
After confirming NS, query an authoritative server directly to verify A/MX/TXT answers.
Waiting for input
Enter a domain, then press Lookup
How to Use
Use NS Lookup (Nameserver Checker) in 4 Steps
01
Enter domain
Type the domain you want to check (e.g. example.com).
02
Lookup NS
Press Lookup to fetch the authoritative nameserver set.
03
Validate authority
Confirm which DNS provider is authoritative for the domain.
04
Troubleshoot
If you’re migrating DNS, confirm old/new zones match before switching.
What is an NS Lookup?
An NS lookup (nameserver lookup) shows which authoritative DNS servers are responsible for a domain. NS records matter because they define the source of truth for the domain’s DNS zone.
Why NS Records Matter
- DNS migrations: when you move between providers, you change the registrar nameservers (NS) and must keep records in sync.
- Propagation debugging: if your NS set is wrong, “waiting for propagation” won’t fix it—resolvers will keep asking the wrong authority.
- Incident response: NS changes can break websites and email; checking NS confirms whether a change was applied.
💡NS records tell you where DNS should be answered from. A DNS propagation checker tells you how widely cached answers have updated.
Authoritative vs Recursive DNS
Authoritative nameservers host your zone file and return final answers. Recursive resolvers (Google, Cloudflare, ISP resolvers) query authoritative servers and cache the results for users.
How to Verify With dig
Use dig to check NS and then query one of the authoritative servers directly:
# Get NS set
dig example.com NS +short
# Query a specific authoritative NS
dig @ns1.yourdnsprovider.com example.com A
Frequently Asked Questions
What does an NS record do?
An NS (nameserver) record lists the authoritative nameservers for a domain. These nameservers host the domain’s DNS zone and are the source of truth for its records.
Why do NS records matter during a DNS provider migration?
When you switch DNS providers, you typically update the registrar nameservers (NS). During the cutover, mismatched zones between old and new providers can cause inconsistent results.
How is NS lookup different from DNS propagation checking?
NS lookup shows which nameservers are authoritative. Propagation checking compares answers from many recursive resolvers to see where caches have updated.
What is the difference between authoritative and recursive DNS?
Authoritative nameservers host the zone data. Recursive resolvers query authoritative servers and cache results for users (ISPs, Google, Cloudflare, enterprise resolvers).
What should I check after changing nameservers?
Verify the NS set, then confirm the authoritative answers for key records (A/AAAA, MX, TXT) from the new provider, and use propagation checks to observe cache convergence.
When to Use
• Switching DNS providers (validate NS cutover)
• Debugging “wrong DNS” issues
• Confirming authority during incidents
CLI Reference
# Find NS
dig example.com NS +short
# Check SOA
dig example.com SOA +short