DNS Propagation Checker
Asks several public DNS resolvers the same question at once and shows where their answers differ. Enter a domain on its own, as "example.com", to compare A records, or add a type, as "example.com MX". Supported types are A, AAAA, CNAME, MX, NS, and TXT.
Asks several public DNS resolvers the same question at once and shows where their answers differ. Enter a domain on its own, as "example.com", to compare A records, or add a type, as "example.com MX". Supported types are A, AAAA, CNAME, MX, NS, and TXT.
After a DNS change, resolvers keep serving the old answer until the record's TTL runs out. Until then some will have the new value and some the old — which is what this tool shows.
Honest limit: these resolvers are anycast, so each one answers from whichever of its nodes is nearest to our server. This compares resolvers, not countries — treat it as a sample, not a worldwide map.
Use cases
- Checking whether a site move to a new IP has reached the big resolvers
- Watching a nameserver change roll out after transferring a domain
FAQ
Is my data sent to a server?
Yes — the queries run on the server, which asks each public resolver on your behalf.
Why do resolvers disagree?
Each caches the previous answer until its TTL expires, and they did not all cache it at the same moment. Disagreement means the change is still in flight.
How long until every resolver agrees?
At most the TTL that was in force before the change, counted from when each resolver last cached the record.
Why does one resolver say the domain was not found?
On a brand-new domain, that resolver has not picked it up yet. It is reported as an answer rather than an error because it is a real signal about propagation.
Does this check every resolver in the world?
No. It checks six large public resolvers. They cover a lot of real traffic, but a resolver run by your own ISP could still hold an old answer.