How to use DNS lookup and propagation tools (and what the records mean)
How to check any domain's DNS records and whether a change has gone live — explained for people who are not DNS engineers.
A DNS lookup tells you what a domain actually resolves to right now. It is the first thing to check when a website "is not working", when email is not arriving, or when you have just changed something and want to know if it has taken effect. Our free DNS lookup tool and DNS propagation checker do this from your browser in seconds.
The records you will meet
| Record | What it is for | Example |
|---|---|---|
| A | Maps a name to an IPv4 address | example.com → 203.0.113.10 |
| AAAA | Maps a name to an IPv6 address | example.com → 2001:db8::1 |
| CNAME | Aliases one name to another | www → example.com |
| MX | Where email for the domain should go | mail.example.com |
| TXT | Free-text data — SPF, DKIM, verification | v=spf1 ... |
| NS | Which nameservers are authoritative | ns1.example.com |
| CAA | Which CAs may issue certificates | 0 issue "letsencrypt.org" |
| SRV | Service location (chat, VoIP, game servers) | _minecraft._tcp.example.com |
When to use a lookup
A site will not load. Look up the A/AAAA record. If it points somewhere unexpected (or nowhere), you have found the problem before touching the server.
Email is bouncing or landing in spam. Check MX, then the TXT records for SPF and DKIM. A missing or broken SPF is the single most common deliverability cause.
You just changed something. Use the propagation checker to compare several public resolvers. If some show the old value, it is caching — wait out the TTL.
Before adding a service. Confirm which nameservers are authoritative (NS) so you edit records in the right place.
How to read the results
The tool queries public resolvers (via DNS-over-HTTPS) directly from your browser, so the answer you see is the answer most of the internet sees. TTL (time-to-live) is how many seconds a resolver may cache the answer — a TTL of 300 means a change can take up to five minutes to be seen everywhere; 86400 means up to a day. Lower the TTL before a planned change to make it propagate faster.
Common gotchas
Old value still showing? That is caching, not a mistake. Compare resolvers with the propagation checker.
CNAME at the apex. You cannot normally put a CNAME on the bare domain (
example.com); use A/AAAA or your provider's "ALIAS/ANAME" record.Trailing dot. In DNS,
example.com.(with a dot) andexample.com(without) can behave differently in some panels — be consistent.
Once you know what is wrong, DNS records explained covers editing them, and our Managed DNS service covers hosting the zone itself.