DNS propagation checker

DNS has no push step to watch: a resolver answers from its cache until the record's TTL runs out, then asks the authoritative servers again. That is why a change “propagates” at different moments per resolver, and why a mixed result here is normal mid-transition behavior rather than a fault; the TTL window in the result is how long the disagreement can last. This tool compares four well-known public resolvers, not every resolver worldwide, and it cannot see your own ISP's cache or a resolver that ignores TTLs. If a resolver's endpoint refuses browser cross-origin reads, its row says unavailable instead of quietly disappearing.