DNS Propagation Checker Resolvers
A DNS propagation check shows whether a record change has reached the resolvers people actually use. Enter a name and record type: the tool asks the domain's authoritative nameservers for the current answer, then asks ten public resolvers and marks each one as matching or still serving an older cached copy.
How to read the results
The first table lists the zone's authoritative nameservers and the answer each one gives when asked directly, without recursion. This is the source of truth. If you have just edited a record and the old value still appears here, the change has not been saved or has not yet synced between your DNS provider's servers, and no amount of waiting on resolvers will help.
The second table lists public resolvers. Each row shows the answer that resolver returns now, whether it matches the authoritative answer, and the cache TTL left: the number of seconds before that resolver discards its copy and asks again. A resolver marked "Differs" with 40 minutes of TTL left will switch to the new value within 40 minutes.
The tool sends its queries from one location. Large public resolvers are anycast networks with many sites that cache independently, so this is a comparison of resolver caches as seen from our server, not a map of countries. A match here means the nearest site of that resolver has the new record.
Why resolvers disagree
- Caching. The usual reason. Each resolver stored the old answer at a different moment, so each one expires it at a different time.
- Negative caching. If a resolver looked up the name before the record existed, it cached the "no such record" answer. That is held for the negative TTL set in the zone's SOA record, which is often longer than people expect.
- Geo and load-balanced DNS. CDNs and global load balancers return different addresses depending on where the query comes from. Resolvers will show different A records permanently, and that is by design.
- Nameserver change in progress. After moving a domain to a new DNS provider, resolvers keep using the old nameservers until the delegation's TTL at the registry expires, commonly up to 48 hours. Compare NS records to see which set each resolver is following.
- Filtering resolvers. Security-focused resolvers intentionally block some names and return no answer or a block page address.
Making a change propagate faster
- Lower the TTL first. A day or more before a planned change, reduce the record's TTL to 300 seconds. Once the old, long TTL has expired everywhere, make the change, then raise the TTL again.
- Check the authoritative servers before anything else. If they disagree with each other, fix that at the DNS provider.
- Flush what you control. Your own computer and browser keep a cache too. Google Public DNS and Cloudflare both offer a public page for purging a name from their caches.
- Keep the old service running. Until every cache has expired, some visitors and some mail will still arrive at the old address.
To see every record on the domain rather than one type, use the DNS Record Lookup. For mail-related changes, the MX lookup and TXT lookup show the records in a form that is easier to read.
Frequently asked questions
How long does DNS propagation take?
At most the TTL of the record you replaced, counted from the moment each resolver last cached it. With a 300-second TTL nearly every resolver has the new value within five minutes. With a one-day TTL it can take up to a day. Nameserver changes at the registrar can take up to 48 hours.
What is the difference between an authoritative nameserver and a resolver?
Authoritative nameservers hold the actual records for a zone and answer for it directly. Resolvers, such as the ones run by an ISP or a public DNS service, look answers up on behalf of users and cache them. A change is live on the authoritative servers at once and reaches resolvers as their caches expire.
Why do some resolvers still show the old record?
They cached the old answer before the change and will keep returning it until its TTL runs out. The "cache TTL left" column shows how long that will be for each resolver.
Can I force DNS to propagate?
Not globally. You can clear your own device's cache, and a few public resolvers provide a purge page for individual names, but most caches simply have to expire. Lowering the TTL before the change is the only way to shorten the wait for everyone.
Does this check DNS from different countries?
No. All queries leave from one server, and each public resolver answers from its nearest site. The tool compares the major public resolvers with the authoritative answer, which shows whether a change has spread, but it does not test separate geographic locations.
Last updated: