DNS Propagation Checker: Free Resolver Check

A DNS propagation checker shows whether DNS resolvers are returning the record you expect after a change. This free tool queries the Cloudflare and Google public resolvers for your domain and record type, then lists the first value each one returns so you can spot old and new answers side by side.

What Is DNS Propagation?

DNS propagation is the period after a DNS change when different resolvers still hand out the old record because they cached it earlier. Nothing is actually pushed across the internet. Each resolver simply keeps its saved answer until the record's TTL (time to live) runs out, then asks again and picks up the new value.

TTL is set in seconds on each record. A TTL of 3600 means a resolver may reuse its answer for up to one hour. A TTL of 86400 means up to a day. That is why two people can load the same domain at the same moment and reach different servers.

Propagation matters whenever you change hosting, move a site to a new IP address, switch email providers, add a verification record, or change nameservers.

What Does This Tool Actually Check?

This tool compares the answers from two large public resolvers, Cloudflare and Google, for the domain and record type you choose. It is a quick comparison, not a map of the entire world.

The page itself says it plainly: two resolver responses cannot confirm worldwide propagation. If both resolvers show your new value, that is a good sign. If one shows the old value and one shows the new one, you have caught propagation in progress. Resolvers run by internet providers, companies and universities keep their own caches and may still differ.

How to Use the DNS Propagation Checker

1. Type your domain into the Domain Name field, for example example.com. If you paste a full web address, the tool reduces it to the host name.
2. Open the Record Type menu and pick A, AAAA, CNAME, MX, NS, TXT or SOA. The default is A.
3. Press Compare Resolvers. The button changes to Checking... while the lookups run.
4. Read the heading "Resolver answers for" followed by your domain and record type.
5. Check the table. Each row shows the Resolver, the Service, the First IP / Value and the Status.
6. Compare the value in each row with the value you set at your DNS host. Run the check again later if they differ.

Worked Example: Moving a Site to a New IP

Say you moved example.com from the old IP 203.0.113.10 to the new IP 198.51.100.25 and the old A record had a TTL of 3600. Right after the change, you select the A record type and press Compare Resolvers.

The Cloudflare row shows 198.51.100.25 with the status Answer returned. The Google row shows 203.0.113.10, also with the status Answer returned. The summary reads 100% of queried resolvers returned a record.

The 100% does not mean you are done. It only means both resolvers had an answer. The values are what matter, and here they disagree, so Google is still serving its cached copy. Wait up to the old TTL (about an hour in this case), run the check again, and look for both rows to show 198.51.100.25.

How to Read the Results

Each row gets one of three statuses, and the value column tells you whether the answer is the one you want.

What the percentage means

The percentage is the share of the two queried resolvers that returned any record. With two resolvers it can only be 0%, 50% or 100%. It says nothing about whether the value is correct, so always read the value column.

Why only one value appears

The table shows the first value returned for the record type. A domain with several A records or several MX records may have more than one answer. For a full list of every record, run a complete DNS lookup and compare it with what you configured.

How Long Does DNS Propagation Take?

For most record changes, propagation finishes within the old record's TTL, which is often between a few minutes and a few hours. Nameserver changes at the registrar commonly take longer, and many registrars quote up to 48 hours.

Plan ahead to shorten the wait. A day or two before a planned migration, lower the TTL of the record you will change to 300 seconds (five minutes). Make the change after the old TTL has expired, then raise the TTL again once everything is stable. A low TTL means resolvers re-ask more often, so your update reaches them sooner.

Who Uses a DNS Propagation Check?

• Site owners moving hosts: confirm the new IP is being served before you shut down the old server.
• Email administrators: verify new MX records after switching mail providers, and confirm SPF or DKIM TXT values are visible.
• Developers and agencies: check a staging or launch domain just before going live.
• SEO professionals: make sure a migration or domain change is resolving consistently so crawlers do not reach a stale server.
• Support teams: settle the question of whether a customer's problem is a cached record or a wrong record.

Best Practices and Troubleshooting

Enter the right hostname

Records are set per hostname. If you changed the record for www.example.com, check that exact name, not the bare domain. Checking the wrong one is the most common reason a result looks unchanged.

Match the record type to the change

A site pointing through an alias uses a CNAME, while one pointing to an IP uses an A or AAAA record. A hostname with a CNAME will not return an A answer of its own in the way you might expect, so choose the type you actually edited. To dig into aliases, try a CNAME record lookup.

Both resolvers show the old value

If both rows still show the old value after the TTL has passed, the change may not have been saved at your DNS host, or you may be editing a zone that is not authoritative because the domain uses different nameservers. Check the NS record type to see which nameservers the domain actually uses, then edit the zone there.

No answer for a record you just added

Look for typos in the name or value, a missing trailing dot where your host requires one, or the record being added to the wrong zone. For TXT records, quotes and stray spaces in long values are a common cause.

Check IPv6 separately

An A record update does not change IPv6. If your site also has an AAAA record, check it too, or inspect it with an AAAA record lookup, so visitors on IPv6 do not land on the old server.

Test the right thing in your browser

Your own computer and router keep DNS caches too. If the tool shows the new value but your browser still reaches the old site, restart the browser, flush your operating system's DNS cache, or try a different network.

Limitations to Keep in Mind

This tool queries two resolvers, so it is a spot check. It cannot tell you what every provider in every country is serving, and it does not display a list of locations. It also does not mark a result as correct or incorrect: you decide that by comparing the value shown with the one you set.

Only the first value of each answer is displayed, and the tool does not show TTL values. If you use DNSSEC and see unexpected failures, a DNSSEC validator can help rule out signing problems. For the full picture of IPs, hosting and network data, browse the Network and IP tools. If you only need to confirm which address a hostname uses, the A record lookup is a focused option.

Enter your domain above, choose the record type you changed and press Compare Resolvers. In a few seconds you will know whether Cloudflare and Google agree with your new record, and whether it is time to wait, recheck or fix the record at your DNS host.