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DNS Lookup

Query DNS records for any domain. View A, AAAA, MX, NS, CNAME, TXT, and SOA records instantly.

Record type

Compare resolvers to watch a change propagate, or ask the authoritative server what was actually published.

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.

How a name is resolvedYour device asks a single resolver. The resolver follows the delegation down from the root, then keeps the answer for the record's TTL.
  1. Your device

    Asks its resolver:

    example.com A ?
  2. Recursive resolver1.1.1.1

    Answers from its cache if it holds the record. Otherwise it asks each level in turn, from the root down.

  3. Root server (.)

    Does not know example.com: refers to the .com servers.

    com. NS a.gtld-servers.net.
  4. .com server

    Refers to the servers of example.com.

    example.com. NS ns1.example.com.
  5. Authoritative server

    Holds the zone and answers, with a TTL of 3,600 seconds.

    example.com. 3600 A 192.0.2.10
  6. Answer cached, then returned

    The resolver keeps the answer for one hour and returns it. Until the TTL runs out, everyone using it gets 192.0.2.10, even if the record has changed: that is the propagation delay.

the MX records of gmail.com, asked to Cloudflare's resolver (1.1.1.1): five mail servers in order of priority.

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 guides

Related tools

Go further

Network glossary: Reverse DNS, Anycast, TTL

Run a visual traceroute to this host