How do you check DNS propagation across global resolvers?
Type the hostname and run the check. The tool queries A and AAAA on the local resolver and on three fixed resolvers: Cloudflare, Google, and Quad9. It never sends your text as a resolver address. The result lists each answer and says whether the sets match.
- Enter one hostname. Do not enter a resolver address. The tool will not use one.
- Read the A and AAAA lines for local, Cloudflare, Google, and Quad9.
- If any lookup failed, treat the row as incomplete. That is not agreement.
- If the sets differ, wait for the TTL and check again before you change more records.
How do you read A, AAAA, CNAME, MX, NS, and TXT propagation results?
Read A as IPv4 and AAAA as IPv6. Matching sets mean those resolvers share the same addresses. CNAME, MX, NS, and TXT are not compared here. Use the DNS record lookup for those types. A mismatch means one resolver still holds the previous answer.
| Record | What this checker does |
|---|---|
| A | Compared across the local resolver, Cloudflare, Google, and Quad9. |
| AAAA | Compared the same way. An empty list is a real answer when every resolver is empty. |
| CNAME | Not queried. Follow it with the DNS record lookup. |
| MX | Not queried. Mail routing is a different check. |
| NS | Not queried. Name servers tell you who serves DNS, not this address comparison. |
| TXT | Not queried. SPF and verification TXT records stay on the DNS record lookup. |
Why do some ISP resolvers still show the old IP address for 24–48 hours?
Resolvers cache records until the TTL expires. Some networks keep a stale answer for 24 to 48 hours after the authoritative server has changed. A mismatch in this check is that cache, not a second website. The explainer of how long DNS propagation takes covers the wait.
- A long TTL keeps the old IP in a resolver until that timer ends.
- Four public resolvers can agree while a home router still shows the old address.
- This page does not claim every network on earth has updated.
- Flushing a local cache does not flush an ISP cache.
How do you lower your DNS TTL before migrating a live website?
Lower the TTL a day or two before you change hosts, then wait out the old value so caches are already short. Point the domain at the new host and run this check again. The guide to point a domain to hosting shows the name-server and A-record choices.
- Note the current TTL on the A and AAAA records you will change.
- Set a short TTL, then wait at least as long as the old TTL before the cutover.
- Change the address or the name servers, not both at random, and run this check.
- Raise the TTL again only after the four resolvers agree and the site answers.