What “propagation” really is
DNS changes don't spread outward; each resolver keeps its cached answer until the record's TTL expires and then asks again. “Propagation” is simply those caches expiring at different times.
This tool asks ten public resolvers (Google, Cloudflare, Quad9, OpenDNS and others) for the same record using DNS-over-HTTPS and highlights answers that differ from the majority.
Reading the results
- All match — the change is visible everywhere these resolvers serve. Your own device or ISP may still cache the old value; flush your DNS cache if needed.
- Different answers — either caches haven't expired yet, or the domain intentionally returns different answers (geo-DNS, CDNs, load balancing).
- NXDOMAIN or no answer — the record doesn't exist or the resolver timed out.
Making changes propagate faster
- A day before the change, lower the record's TTL (for example to 300 seconds).
- Make the change, then confirm here and with a DNS lookup.
- Raise the TTL again once everything is stable.
Questions
How long does DNS propagation take?
Up to the old record's TTL — often minutes to a few hours, occasionally up to 48 hours for name server (NS) changes at the registry.