The records you will see
| Record | What it does |
|---|---|
| A | Points a name to an IPv4 address, such as the server for your website. |
| AAAA | The same, for an IPv6 address. |
| CNAME | Makes one name an alias of another. Often used for www. |
| MX | Says which servers receive email for the domain, with a priority. |
| TXT | Free text. Used for SPF, DMARC, DKIM and proof you own the domain. |
| NS | Lists the name servers that hold the domain’s records. |
| SOA | Administrative details about the zone, including its serial number. |
| CAA | Which certificate authorities may issue HTTPS certificates for the domain. |
TTL and propagation
Each record has a TTL (time to live), in seconds. It tells resolvers how long they may remember an answer. A TTL of 3600 means up to an hour. When you change a record, some people see the new value straight away and others still see the old one until their copy expires. That gap is what people call propagation.
The DNS lookup asks Cloudflare, Google and Quad9 at the same time, so you can see whether they agree.
Mistakes that break things
- Two SPF records. You can have only one. See the SPF, DKIM and DMARC guide.
- A CNAME on the bare domain. The root of a domain (
example.co.uk) cannot be a CNAME if it also needs MX or TXT records. Use an A record there. - Changing name servers without copying records. The new name servers start empty, so your website and email stop working until you recreate them.
- Forgetting the www version. Visitors type both. Point both at your site.
- A very long TTL before a change. Lower it a day ahead so the change spreads quickly.
Where DNS is managed
Records live at whoever runs your name servers. That might be your registrar, your hosting company or a service like Cloudflare. The NS records tell you which. Our domain checker names the provider for you.
See every record for a domain and compare three resolvers side by side.
Look up DNS records