DNS Lookup
Query DNS records for any domain. View A, AAAA, MX, NS, CNAME, TXT, and SOA records instantly.
About DNS lookups
A DNS lookup asks the naming system what a domain currently resolves to. It is the first thing to check when a site is unreachable but the server is up: if the A record points somewhere unexpected, or the record has not propagated yet, nothing downstream will work no matter how healthy the host is.
Read the answer alongside its TTL. A short TTL means the record was recently changed or is deliberately agile; a long one means resolvers may serve the old value for hours after you update it. MX records tell you who handles the domain's mail, NS records who is authoritative for it, and a missing SOA usually means the domain is not delegated at all.
Frequently asked questions
- Why does my DNS change not show up yet?
- Resolvers cache answers for the length of the record's TTL. Until that expires, they keep serving the previous value. Lower the TTL before a planned change and the switch becomes near-instant.
- What is the difference between A and AAAA?
- A maps a name to an IPv4 address, AAAA to an IPv6 one. A domain can have both; which is used depends on what the client and its network support.
- Why do I get a different answer than my colleague?
- You are probably using different resolvers, each with its own cache. Anycast and geo-aware DNS also return different addresses depending on where the query comes from, which is intended, not a fault.
- Does this tool query authoritative servers?
- It resolves through a recursive resolver, so you see what a normal client would see, cache included. That is usually what you want when diagnosing a user-facing problem.
Related tools
Go further
Network glossary: Reverse DNS, Anycast, TTL