Is your DNS change
live yet?

When you change a DNS record, your DNS host updates its nameservers within seconds. But resolvers, the DNS servers people's devices actually ask, keep a cached copy of the old answer until its time to live (TTL) runs out. Propagation is the time it takes for those cached copies to expire everywhere, so everyone gets the new answer.

As long as the old record's TTL, at most. A record with a TTL of 300 seconds is updated everywhere within five minutes; one with a TTL of 86,400 can take a day. Nameserver changes at the registrar take longer, often up to 48 hours, because the registry's own NS records usually carry a long TTL. The checker shows how long each resolver will keep its current copy.

It finds the nameservers that serve the domain and asks each of them for the record: that's the current answer. Then it asks 19 public resolvers, including Google, Cloudflare, Quad9, OpenDNS, AliDNS, Yandex and KT, what they return, and compares. A resolver with a different answer still has the old record cached.

If the old record is still cached, the resolver updates when its TTL runs out. If the difference stays, your site may be behind a CDN or load balancer that gives different addresses in different places, which is normal. The nameservers' answer is always the one you set.

Lower the record's TTL to 300 seconds a day before a planned change, so caches expire quickly when you make it. After a change you can ask Google Public DNS and Cloudflare to drop their cached copy on their cache flush pages. Your own computer caches DNS too: restarting the browser or flushing the operating system's DNS cache helps.

A domain usually has two or more nameservers that should all return the same records. If they disagree, visitors get different answers depending on which one their resolver asks. It usually clears within minutes as the DNS host syncs its servers; if it doesn't, contact your DNS host.

Yes. The Lemon Domains MCP server has a check_propagation tool, the REST API serves the same check at GET /api/v1/propagation, and the lemon CLI runs it with lemon propagation example.com. An agent that changes DNS through Lemon Domains can check the change has gone live straight after.