Understanding DNS records

DNS records are the instructions that tell the internet where to find your website, where to deliver your email and how to verify your domain with other services. Each record has a name (host), a type, a value and a TTL.

The records you will use most

• A: points a name to an IPv4 address, such as the IP of your hosting account or cloud server. Example: @ A 203.0.113.10.
• AAAA: the same as an A record, for an IPv6 address.
• CNAME: makes one name an alias of another name. Example: www CNAME example.com.. A CNAME cannot sit on the root of the domain, and a name with a CNAME cannot have other records.
• MX: tells other mail servers where to deliver email for your domain. Each MX has a priority, and lower numbers are tried first.
• TXT: free-form text used for email authentication (SPF, DKIM, DMARC) and for proving domain ownership to services such as search consoles and email platforms.
• NS: lists the nameservers responsible for the domain or for a delegated subdomain.

In most DNS editors, @ means the root domain itself, such as example.com, and a name like www or shop means that subdomain.

TTL: how long answers are cached

The TTL (time to live) is how many seconds resolvers may cache a record before asking again. A common default is 3600 (one hour). Before a planned change, such as moving your website to a new server, lower the TTL of the affected records to 300 a day in advance. The switch then takes effect for most visitors within minutes, and you can raise the TTL again afterwards.

Common setups

• Website on a cloud server: an A record for @ and an A record (or a CNAME to the root) for www, both pointing to the server's public IP from its Access details.
• Business email: the MX records provided for your mail service, plus an SPF TXT record listing every service that sends mail for the domain.
• Verifying a third-party service: add the TXT or CNAME record the service gives you exactly as shown, then complete verification in that service.

Mistakes to avoid

• Having two SPF records. A domain must have a single SPF TXT record that includes all senders.
• Deleting MX records while changing website records, which stops incoming mail.
• Pasting a full URL, such as https://example.com, into a record value. Records take hostnames or IP addresses only.
• Editing records at a DNS service that is not the one your nameservers point to. The changes will have no effect.

Records are edited in the DNS service your nameservers point to. If you need help deciding what to add, open a ticket with the domain name and what you are trying to achieve.