DNS Lookup

Dig-style lookup for A, AAAA, MX, TXT, NS, SOA, SRV, CAA, PTR — plus subdomain sweep.

For PTR (reverse) lookups, enter an IPv4 address, e.g. 8.8.8.8

Related tools

DNS PropagationQuery one record across 14 public resolvers in the US and worldwide to spot propagation lag.WHOIS LookupRegistration, registrar, dates and nameservers for a domain (live WHOIS).SPF CheckerFetch an SPF record and recursively count DNS lookups against the 10-lookup limit.DMARC CheckerRead and explain a domain's DMARC policy (p, rua, pct, alignment).IP InfoReverse DNS plus ASN, network and country for an IP (via Team Cymru).

Frequently asked questions

What is a DNS lookup?

A DNS lookup asks the Domain Name System what records a name publishes — for example the A record (IPv4 address), MX records (mail servers) or TXT records (SPF, DKIM, verification). It is the web equivalent of the classic dig command.

Which DNS record types can I query?

A, AAAA, CNAME, MX, NS, TXT, SOA, SRV, CAA and PTR (reverse). You can also run "All common records" in one query, or a subdomain sweep of standard names like www, mail and autodiscover.

Why do different resolvers return different answers?

DNS answers are cached for a period set by each record's TTL. Right after a change, some resolvers may still serve the old value until their cache expires. Comparing Google, Cloudflare and Quad9 shows how far a change has propagated.

How do I do a reverse DNS (PTR) lookup?

Choose the PTR record type and enter an IPv4 address such as 8.8.8.8. The tool builds the in-addr.arpa name and returns the host name that address points to.

What is a TTL and why does it matter?

TTL (time to live) is how many seconds a resolver may cache a record before asking again. A low TTL means changes appear quickly but generates more queries; a high TTL is efficient but slows down updates.

What is the difference between an A and an AAAA record?

An A record maps a name to a 32-bit IPv4 address, while an AAAA record maps it to a 128-bit IPv6 address. A domain can publish both so clients use whichever protocol they support.

What is a CNAME record and where can I use one?

A CNAME is an alias that points one name at another canonical name. You cannot place a CNAME at the zone apex (the bare domain) alongside other records, so it is used for subdomains like www.

What does an SOA record contain?

The SOA (Start of Authority) record holds the primary name server, the administrator email, the zone serial number and the refresh, retry, expire and minimum TTL timers that govern how secondaries and resolvers treat the zone.

What is a CAA record for?

A CAA record lists which certificate authorities are permitted to issue TLS certificates for your domain, reducing the risk of an unauthorized authority issuing a certificate in your name.