You have changed an A record or moved nameservers. It works for you, but a colleague still sees the old site. The propagation checker asks twenty public resolvers around the world what they are currently serving, so you can see exactly who has the new value and who has not.
What it is
Read more
Why it matters
Read more
This is not DNS monitoring
Running a check
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Open DNS propagation. It is in the sidebar under Tools.
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Type the domain. A full address works too: anything before the host name and anything after it is stripped, so
https://example.com/pageis read asexample.com. -
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Pick the record type. It starts on A, which is the right choice for "has my site moved yet".
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Press Check propagation. The results appear within a few seconds.
Reading the result
The top of the result gives three counts and the most common answer:
- Match. Resolvers that replied with exactly the most common answer.
- Mismatch. Resolvers that replied with something different. This is the stale cache you are hunting for, and each mismatching value is highlighted in the list below.
- Timeout. Resolvers that gave no usable answer at all. This bucket covers three different cases: the resolver timed out, the query failed, or it replied with nothing.
Below the counts is the full list, one row per resolver, with its name, location, address, how long it took in milliseconds, and what it returned. A resolver that returned nothing shows timed out, no answer or error in place of a value, so you can tell an unreachable resolver from one that answered "this record does not exist".
How the most common answer is chosen
When resolvers time out
Each resolver gets two seconds to answer, and the whole check gives up after four. A handful of timeouts on any given run is normal: these are public resolvers on the open internet, some of them rate-limit, and a few are simply slow to reach from our servers. Treat timeouts as no information rather than as a problem with your domain. What matters is the split between match and mismatch among the resolvers that did reply.
What it cannot tell you
- How much longer. It reports the state right now. It does not predict when a stale resolver will refresh, because that depends on the cached lifetime of the old record, not the new one.
- Whether the record is correct. It reports what resolvers are serving, not whether that value is the one you meant to publish.
- Your visitors' own resolvers. The list is twenty well-known public resolvers. Most people use whatever their internet provider gives them, and those are not on the list.
Who can open it
The in-dashboard version is available on Starter, Pro and Agency. Free accounts are held to their own one-page dashboard and cannot open it. If you are on the free plan, use the public checker instead, which works the same way.
There is also a public version at /tools/dns-propagation-checker, open to anyone. It asks for an email address before it will run a check, and limits visitors who are not signed in to twenty checks a day. The dashboard version does neither: no email, no daily limit.
Where to find this
Run a check against twenty resolvers.
Learn moreThe same check on a public page, with a world map.
Good to know
- Running a check costs nothing and uses no credits.
- Nothing is saved. Re-run the check to see the current picture; there is no history.
- A mismatch is usually a cache that has not expired yet, not a mistake. Re-check in an hour before changing anything.
- To be told automatically when a record changes, switch on DNS monitoring for that site instead.