DNS Lookup

What is DNS?

The Domain Name System (DNS) translates human-readable domain names like example.com into IP addresses that computers use to find each other on the internet. It's often called the "phone book of the internet." When you visit a website, your browser queries DNS to find the server's IP address before it can connect.

Record types explained

A — Address record

Maps a domain to an IPv4 address (e.g. 93.184.216.34). This is the most fundamental record type — it's how browsers find where a website is hosted.

AAAA — IPv6 address record

The IPv6 equivalent of an A record. Maps a domain to a 128-bit IPv6 address (e.g. 2606:2800:220:1:248:1893:25c8:1946).

MX — Mail exchange

Specifies the mail servers responsible for receiving email for the domain. MX records include a priority value — lower numbers have higher priority. When sending email to user@example.com, the sending server queries MX records to find where to deliver.

TXT — Text record

Holds arbitrary text data. Commonly used for SPF records (email authentication), DKIM keys, DMARC policies, and domain ownership verification (Google, Microsoft, etc). A single domain can have multiple TXT records.

CNAME — Canonical name

An alias that points one domain to another. For example, www.example.com might be a CNAME pointing to example.com. The resolver then follows the chain to find the final A/AAAA record. CNAMEs cannot coexist with other record types at the same name.

NS — Name server

Specifies the authoritative DNS servers for the domain. These are the servers that hold the definitive DNS records for the zone. When you register a domain, your registrar sets NS records to point to your DNS provider.

SOA — Start of Authority

Contains administrative metadata about the DNS zone: primary name server, responsible party's email, zone serial number, and timing parameters for refresh, retry, expire, and minimum TTL.

PTR — Pointer record

Maps an IP address back to a domain name (reverse DNS). Used by mail servers to verify the sending server's identity and by network tools for hostname resolution.

What is TTL?

TTL (Time To Live) is the number of seconds a DNS record can be cached by resolvers before they must query the authoritative server again. A low TTL (e.g. 300s / 5 minutes) means changes propagate quickly but generate more DNS traffic. A high TTL (e.g. 86400s / 1 day) reduces queries but means changes take longer to reach all users.

DNS propagation

When you change a DNS record, the update doesn't take effect everywhere instantly. Resolvers worldwide have cached the old record for up to its TTL duration. "DNS propagation" is the time it takes for all caches to expire and pick up the new record. This typically takes anywhere from a few minutes to 48 hours, depending on the old record's TTL and resolver behaviour.

To speed up propagation before making changes, lower the TTL in advance (e.g. set it to 60 seconds a day before the migration), make the change, then raise the TTL back to a normal value.

About this tool

This tool queries Google's public DNS over HTTPS API (dns.google). Results reflect what Google's resolvers see, which may differ slightly from your local resolver if records were recently changed and caches haven't expired yet.