DNS 3RD-PARTY API

Free DNS Lookup Tool

Check the live DNS records for any domain, hostname or IP address. View DNSSEC status, exact TTLs and clearly structured results; nothing is stored.

Checks the common record types together.

What is a DNS lookup?

A DNS lookup asks the Domain Name System for the records published for a domain or hostname. These records connect names to web servers, mail systems and other internet services, and they also publish security and verification policies.

Use this tool to inspect the common records together, query one specific record type, check a service name such as _sip._tcp.example.com, or enter an IP address to perform a reverse PTR lookup.

DNS record types

AIPv4 address

Maps a hostname to an IPv4 address, such as 192.0.2.10.

AAAAIPv6 address

Maps a hostname to a 128-bit IPv6 address.

MXMail exchange

Lists the servers that accept email for a domain. Lower priority numbers are preferred.

TXTText and verification

Publishes text used by SPF, site verification and other domain policies.

NSName server

Identifies the authoritative name servers responsible for a DNS zone.

CNAMECanonical name

Makes one hostname an alias of another hostname.

CAACertificate authority

Controls which certificate authorities may issue TLS certificates for a domain.

SOAStart of authority

Describes the zone's primary server, serial number and refresh timing.

SRVService location

Publishes the hostname, port, priority and weight for a named service.

PTRReverse DNS

Maps an IPv4 or IPv6 address back to a hostname when reverse DNS is configured.

How to read the results

TTL and DNS propagation

The time to live (TTL) tells recursive resolvers how long an answer may be cached. After a DNS change, an older answer can remain visible until its previous TTL expires.

DNSSEC validation

“Validated” means the resolver verified the DNSSEC signatures for the answer. “Not validated” does not automatically mean a record is unsafe; the zone may not use DNSSEC.

NXDOMAIN

NXDOMAIN means the queried domain or hostname does not exist in DNS. This is different from a valid name that simply has no record of the selected type.

SERVFAIL and query failures

SERVFAIL indicates that a resolver could not complete the lookup. Network and provider failures are shown as warnings rather than being reported as missing records.

How D4N performs DNS lookups

The tool sends encrypted DNS-over-HTTPS queries to Cloudflare's public recursive resolver. If Cloudflare cannot complete a query, Google Public DNS is used as a fallback and the result is labelled clearly. D4N does not store your lookup history on its servers; recent searches are saved only in your browser.

Recursive versus authoritative answers: recursive resolvers may return a cached answer. This tool shows the remaining TTL and resolver provenance so you can interpret freshness correctly. It does not currently query every authoritative name server directly.

DNS lookup questions

How long do DNS changes take?

Changes can appear quickly at the authoritative server, but recursive resolvers may keep the previous answer until its TTL expires. Different users can therefore see different answers temporarily.

Can I look up a subdomain?

Yes. Enter the complete hostname, such as www.example.com, and select all records or one specific type.

How do I run a reverse DNS lookup?

Enter an IPv4 or IPv6 address. The tool automatically converts it to the appropriate reverse-DNS name and requests its PTR record.

Why is a record missing?

The record may not be configured, may exist under another hostname, or may still be hidden by caching. Query failures are displayed separately so they are not mistaken for confirmed absence.

Are DNS searches private?

D4N does not store the query, but the selected public DNS resolver receives the hostname or address required to answer it.

Is this an authoritative DNS check?

No. It is a recursive lookup designed to show what a public resolver currently returns. Direct authoritative-server diagnostics are a separate, deeper test.