How long does propagation take?

There is no push: each resolver keeps the old answer until its cached TTL expires.

Why do resolvers disagree?

They cached the record at different times, or some see a different nameserver while a delegation change spreads.

DNS Propagation

DNS propagation is the time it takes for a changed record to replace cached copies at resolvers around the world, which depends on the old record’s TTL. This check asks public resolvers in several regions for the same record and compares their answers.

When to use this: You changed a DNS record and want to know whether resolvers everywhere see the new value yet. Command prefix propagation:

About the DNS Propagation

Ask public resolvers around the world for the same record and compare their answers to see whether a change has reached them.

FAQ

How long does propagation take?: There is no push: each resolver keeps the old answer until its cached TTL expires.
Why do resolvers disagree?: They cached the record at different times, or some see a different nameserver while a delegation change spreads.