DNS Propagation Checker

See how consistently a DNS record is currently returned by several independent public recursive DNS resolvers, compared against the domain's own authoritative answer.

What is a DNS propagation checker?

A DNS propagation checker shows whether a DNS change has reached the resolvers that people's devices actually use. After you edit a record, resolvers keep serving the old value until their cached copy expires, so different users can briefly see different answers. This tool asks six public resolvers for the same record and compares each answer with the official one from the domain's own nameserver.

It answers the practical question behind most DNS changes: is the new value being returned yet?

How DNS propagation works

"Propagation" is really caching. When a resolver looks up a record, it keeps the answer for the record's TTL. Until that time runs out, it keeps returning the stored answer, even if the record has already changed. Once the cache expires, the resolver asks again and picks up the new value. This is why a change can appear instantly for one person and hours later for another.

Resolvers tested

The tool queries six resolvers: Cloudflare (1.1.1.1 and 1.0.0.1), Google (8.8.8.8 and 8.8.4.4), Quad9 (9.9.9.9) and OpenDNS (208.67.222.222). It also finds the domain's nameserver and asks it directly for the authoritative answer to compare against.

How to check DNS propagation

  1. Enter the domain or subdomain you changed, for example www.example.com.
  2. Choose the record type: A, AAAA, CNAME, MX, NS or TXT.
  3. Press Check Propagation.
  4. Compare the authoritative result with each resolver's answer, and repeat after a few minutes if some still differ.

Reading the propagation results

The percentage shows how many resolvers that answered successfully returned the same value as the authoritative nameserver. Timeouts and failures are left out of the percentage completely, so a slow resolver never counts as a mismatch. The percentage only describes the six resolvers tested, not every resolver on the internet.

  • Match: the resolver returns the new, authoritative value.
  • Different: it still returns another value, usually the cached old one.
  • NXDOMAIN: the resolver says the name does not exist.
  • Timeout or Failed: no usable answer arrived within the time limit.

Results are cached for 30 seconds, and the page tells you when you are seeing a cached result rather than a live one.

Planning a DNS change without downtime

A little preparation means visitors barely notice a DNS change.

  1. A day before, lower the TTL of the record you will change, for example to 300 seconds.
  2. Make sure the new server or service is ready and working before anything points to it.
  3. Change the record, then use this checker to watch the new value spread.
  4. Keep the old server running until the tested resolvers match and the old TTL has passed.
  5. Once everything matches, raise the TTL back to its usual value.

Common uses

  • Checking a new A record after moving a website.
  • Watching MX records spread after switching email provider.
  • Confirming a verification TXT record before another service checks it.
  • Checking that a CNAME for a new subdomain, such as a help centre or shop, is live.
  • Seeing whether one resolver lags behind when only some users report a problem.

Common problems and fixes

Resolvers still show the old value. Wait for the old TTL to run out. Next time, lower the TTL a day before the change so caches expire faster.

The authoritative answer is unavailable. The domain's nameserver could not be reached or found. Check the NS records with the NS Lookup.

Too many checks. Each connection can run 10 propagation checks per minute. Wait a minute and try again.

Related tools

Frequently asked questions

How long does DNS propagation take?

It depends on the TTL of the old record. Resolvers keep the old answer until that time runs out, so a record with a one-hour TTL usually updates everywhere within about an hour. Nameserver changes can take up to 48 hours because NS records often have long TTLs.

Why do some resolvers show the new value and others the old one?

Each resolver cached the record at a different moment, so their copies expire at different times. Resolvers that recently refreshed show the new value, while others still serve their stored copy. This is normal and settles once every cache has expired.

Which DNS resolvers does the propagation checker use?

It queries six public resolvers: Cloudflare at 1.1.1.1 and 1.0.0.1, Google at 8.8.8.8 and 8.8.4.4, Quad9 at 9.9.9.9 and OpenDNS at 208.67.222.222. It also asks the domain's own nameserver directly, and uses that authoritative answer as the value the others are compared with.

Does 100% mean the change has reached everyone?

No. It means every tested resolver that answered returned the authoritative value. Internet providers and company networks run many other resolvers with their own caches, and some may still hold the old record until its TTL runs out. A 100% result is a strong sign the change is spreading well.

Can I speed up DNS propagation?

You cannot clear other people's caches, but you can plan ahead. Lower the record's TTL to a few minutes at least one old TTL period before the change. Once the new value is everywhere, raise the TTL again. On your own computer, flushing the local DNS cache can help.

Why are timeouts not counted in the percentage?

A timeout means no answer arrived, so there is nothing to compare. Counting it as a mismatch would make the result look worse than it is, and counting it as a match would hide problems. Timeouts and failures are listed separately so you can see them clearly.

What does NXDOMAIN mean in the results?

NXDOMAIN means the resolver reports that the name does not exist at all. If every resolver agrees, the name has not been created or has been removed. If only some return it, they may have cached a "does not exist" answer from before the record was added.