A plain-language guide to the DNS records every domain owner meets — A, AAAA, CNAME, MX and TXT — with real examples of when you use each.

Every time you type a website address, your computer has to turn that name into a number it can actually connect to. That translation is handled by DNS, the Domain Name System, and the instructions that make it work are called DNS records. If you own a domain, understanding these records is what lets you point your site to a host, set up email, and prove ownership to services like Google.

This guide explains the records you will meet most often, in plain language, with an example of when you would touch each one. You can look up any of them for a live domain with our DNS Lookup tool.

What a DNS record actually is

A DNS record is a single line of configuration stored at your DNS provider. Each record has a type (such as A or MX), a name (the domain or subdomain it applies to), a value (the address or text it points to), and a TTL, or time to live, which tells other servers how long they may cache the answer before checking again.

When someone visits your site, their computer asks a DNS server for your records, gets the answer, and remembers it for the length of the TTL. This caching is why changes are not always instant.

A record

The A record is the most important one. It maps a domain name to an IPv4 address, the four-number address like 203.0.113.10 that identifies your web server. When you move your website to a new host, updating the A record to the new server's IP is what actually moves your traffic.

If your site loads at the wrong place after a migration, the A record is the first thing to check. If it still shows the old server's IP, the change was not saved or has not finished spreading.

AAAA record

An AAAA record does the same job as an A record, but for an IPv6 address, the newer and much longer address format written with colons, like 2001:db8::1. Not every host uses IPv6 yet, so you will not always have one. When you do, it sits alongside the A record so visitors on either address type can reach you.

CNAME record

A CNAME, or canonical name, is an alias. Instead of pointing to an IP address, it points one name at another name. A common use is making www.example.com an alias of example.com, so both lead to the same place and you only have to maintain one address.

One rule catches people out: you cannot put a CNAME on your root domain (example.com with no prefix) if it also has other records, and it must never share a name with an A record. Use CNAMEs for subdomains like www or shop, and A records for the root.

MX record

MX stands for mail exchanger. These records tell the rest of the internet which servers should receive email for your domain. Without correct MX records, email sent to your address bounces or disappears.

Each MX record has a priority number, and the lower number is preferred. Backup mail servers get higher numbers. When you switch email providers, remember to remove the old MX records, not just add the new ones, or some messages may still go to the old service. You can view any domain's mail servers with our MX Lookup tool.

TXT record

A TXT record simply holds a piece of text. On its own that sounds useless, but it powers several essential jobs. Services like Google or Microsoft ask you to add a TXT record to prove you own the domain. Email security also relies on them: SPF, DKIM and DMARC are all stored as TXT records and together they stop other people from sending fake email in your name.

Other records you may see

A few more appear from time to time. NS records list the name servers responsible for your domain, the servers that hold all of the above. SRV records point to specific services such as chat or VoIP. CAA records state which certificate authorities are allowed to issue SSL certificates for your domain. You rarely edit these by hand, but it helps to recognise them.

Why DNS changes take time

When you edit a record, the change is not seen everywhere at once. Servers around the world may still be holding the old answer until its TTL expires. Many changes appear within minutes to a couple of hours, but some can take up to 24 to 48 hours to reach everyone. If you see the old result on your own computer, clearing your DNS cache or restarting your router usually helps.

Frequently asked questions

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

An A record points a name to a numeric IP address. A CNAME points a name to another name. Use an A record for your root domain and CNAMEs for subdomains that should follow it.

How long do DNS changes take to work?

It depends on the record's TTL. Most changes appear within a few hours, but some resolvers keep old values for up to 48 hours.

Why is my email not arriving after changing hosts?

Check your MX records. If they still point to the old provider, or the old records were left in place next to the new ones, delivery can fail. Confirm them with the MX Lookup tool.

How do I see the DNS records for a domain?

Use a DNS lookup tool. Enter the domain name and it returns the A, AAAA, MX, NS, TXT and other records that the rest of the internet sees for it.

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Want to check your own domain? Try the free DNS Lookup, MX Lookup and SSL Checker tools on Toolora.