What propagation really is
DNS does not push changes. The domain's authoritative nameservers have the new record immediately; resolvers keep serving the old answer until its time to live runs out. Propagation is waiting for caches to expire.
This checker asks the authoritative servers directly (the source of truth) and then twelve independent public resolvers. A resolver that differs still has the old answer cached; its TTL says for how long.
What this check cannot show
Most public resolvers are anycast: our query reaches the node nearest our server, and other nodes worldwide have caches of their own. Your provider's resolver is not public. Treat matching results as a strong sign, not proof that every resolver on earth has the change.
Questions
- How do I make changes propagate faster?
- Lower the record's TTL (for example to 300 seconds) a day before the change, make the change, then raise it again.