DNS Lookup

Diagram: A domain query returning several distinct record types from an authoritative source — illustrating dns lookup
A domain query returning several distinct record types from an authoritative source.

Query all major DNS record types for any domain name. See A, AAAA, MX, NS, TXT, and CNAME records as returned by authoritative nameservers. Useful for debugging email delivery, verifying domain configuration, and investigating infrastructure.

DNS Record Types Explained

DNS (Domain Name System) translates human-readable domain names into the addresses computers use. Different record types serve different purposes: For a beginner-friendly primer, read our guide to what DNS is or see how DNS resolution works step by step.

Record Type Full Name Purpose Common Use Case
A Address Maps domain to IPv4 address Website hosting, server routing
AAAA IPv6 Address Maps domain to IPv6 address Modern IPv6-capable infrastructure
MX Mail Exchange Specifies email servers Email routing, spam prevention setup
NS Name Server Identifies authoritative DNS servers DNS delegation, registrar management
TXT Text Arbitrary text data SPF, DKIM, DMARC, Google/Microsoft verification
CNAME Canonical Name Domain alias pointing to another domain CDN configuration, subdomains, service aliases
SOA Start of Authority Zone management metadata TTL defaults, zone transfers, serial tracking
PTR Pointer Reverse DNS - IP to hostname Email deliverability, logging, abuse investigation

How a DNS Lookup Actually Resolves

A lookup is not one question but a chain of them. When a resolver has nothing cached, it walks the hierarchy from the top:

  1. The resolver asks a root server which nameservers are authoritative for the top-level domain (.com, .org, .uk).
  2. It asks the TLD nameserver which nameservers are authoritative for the specific domain.
  3. It asks that authoritative nameserver for the actual record, and receives the answer along with a TTL.
  4. The resolver caches the answer for the TTL duration and returns it. Every later query inside that window is answered from cache without touching the hierarchy again.

This tool queries from our server rather than your machine, so the result reflects what the public DNS system currently holds - not what your ISP or operating system happens to have cached.

Reading TTL Values

Every record returns a TTL in seconds. It is the single most useful number in a lookup because it tells you how long you must wait before a change is guaranteed to be visible everywhere.

TTLTypical useTrade-off
300 (5 min)Immediately before a planned migrationFast propagation, more query load on your nameservers
3600 (1 hour)Records that change occasionallyA reasonable everyday default
86400 (24 hours)Stable records - MX, NS, verification TXTVery low load, but a mistake is visible for a day

The practical rule: lower the TTL at least one old-TTL period before you plan to change a record, make the change, then raise it again once the new value has settled.

Common Lookup Problems and What They Mean

What you seeMost likely cause
NXDOMAINThe name does not exist in the zone at all - check for a typo or a record that was never created.
Empty answer, no errorThe domain exists but has no record of that type. An A lookup on a mail-only subdomain does this.
Old value still returnedA cached copy has not expired yet. Compare against the TTL you set before the change.
Different answers from different toolsNormal mid-propagation. Resolvers expire their caches independently.
SERVFAILThe authoritative nameserver is unreachable or returned a broken response - often a DNSSEC validation failure.

Frequently Asked Questions

How do I check the DNS records for a domain?

Enter the domain in the form above and choose a record type. The tool performs a live query against the public DNS system and returns the current A, AAAA, MX, NS, TXT, or CNAME records with their TTL values. Because the query runs from our server rather than your machine, the answer is independent of your local DNS cache.

Why are my DNS changes not showing yet?

DNS results are cached. Every record has a TTL (time to live), and resolvers around the world keep serving the old value until their cached copy expires - That delay is what people call DNS propagation. Changes typically appear within the old TTL, though some resolvers hold records longer, up to 24-48 hours. Lowering the TTL before a planned change speeds this up.

What is the difference between an A record and a CNAME record?

An A record maps a hostname directly to an IPv4 address (AAAA does the same for IPv6). A CNAME is an alias: it points one hostname at another hostname, which is then resolved in turn. CNAMEs are convenient when many names should follow one target, but a CNAME cannot coexist with other records, which is why the bare domain root normally uses an A record.

Related Tools

Sources & Further Reading

The technical claims on this page are drawn from the primary specifications and vendor documentation below.

  1. RFC 1035 — Domain Names: Implementation and Specification RFC Editor
  2. IANA DNS Parameters Registry IANA