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DNS propagation checker

Changed an A record, moved nameservers or updated MX? Ask ten independent public resolvers for the same record at once and see which ones already return the new value.

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What DNS propagation really is

Nothing is pushed across the internet when you change a DNS record. Your authoritative nameservers start serving the new value immediately. What takes time is that recursive resolvers, the servers your visitors actually ask, keep the old answer until its TTL runs out. Each resolver cached it at a different moment, so each one switches at a different moment.

That is why two people can see two different versions of your site for a while, and why a change with a 300 second TTL settles in minutes while one with an 86400 second TTL can take a day.

How this check works

OrbitProbe sends the same question to ten independent public resolvers: Cloudflare, Google, Quad9, OpenDNS, AdGuard, Yandex, DNS.SB, Verisign, Lumen and CleanBrowsing. Answers are normalised, so the order of records and upper or lower case do not count as a difference, and then grouped. You see how many resolvers returned each distinct answer, and which ones returned no record, said the name does not exist, or could not be reached.

A resolver that failed is shown as failed. It is never counted as agreeing, and the result is only called consistent when every resolver answered and every answer is identical.

What the result does and does not tell you

The result describes these ten resolvers, as seen from our server, at the time shown. It is a good early signal, because these resolvers serve a large share of real users. It is not a measurement of the whole internet, and no tool can give you one: there are millions of resolvers, including the one at every ISP and office.

Most of these resolvers are anycast networks. The node that answered us may not be the node that answers a visitor on another continent, and the two can hold different cached values for a short time.

If the answers disagree

Disagreement shortly after a change is normal. Check the TTL of the old record: that is the longest a well-behaved resolver will keep it. If answers still differ long after the old TTL has passed, query your authoritative nameservers directly. When two of your own nameservers return different values, the zone was not updated everywhere, and that is a fault to fix rather than something to wait out.

For a nameserver move, keep the old zone running and identical until the delegation TTL at the registry, often 48 hours, has passed.

FAQ

How long does DNS propagation take?

As long as the TTL of the record you replaced, counted from when each resolver last cached it. With a 300 second TTL most resolvers switch within five minutes. Nameserver changes depend on the delegation TTL at the registry, which is commonly 48 hours.

Can I speed up DNS propagation?

Not after the change. You can prepare: lower the TTL of the record a day or so before you change it, make the change, and raise the TTL again once everything has settled. Some public resolvers also offer a cache purge page for a single name.

Why do some resolvers still show the old IP address?

They cached the old answer before your change and its TTL has not expired yet. This is expected behaviour, not an error. If it continues well past the old TTL, check that all of your authoritative nameservers serve the new value.

Does 10 of 10 mean the change is live everywhere?

It means all ten resolvers we asked returned the same answer at that moment. That is a strong sign, but it is not proof for every network. An ISP resolver somewhere may still hold the old value until its cache expires.

What does 'no records' or 'name does not exist' mean?

No records means the name exists but has nothing of the type you asked for, for example no AAAA record. Name does not exist (NXDOMAIN) means the resolver found no such name at all. Negative answers are cached too, so a newly created name can show as missing for a while.

Which record types can I check?

A, AAAA, NS, MX, TXT and CNAME. Pick the type that you changed. For a website move that is usually A or CNAME on the www name; for a mail move it is MX; for a DNS provider move it is NS.