DNS propagation checker
A DNS change does not take effect everywhere at once: resolvers keep serving the old answer until its TTL expires. Enter a domain and a record type — the same question goes to six major public resolvers and their answers are compared.
Why resolvers disagree
Nothing actually propagates in DNS. The authoritative server changes the record instantly; the disagreement comes from caching. Each resolver keeps an answer for exactly as many seconds as the record's TTL says and asks nothing until then. So Cloudflare can hand out the new address while your ISP's resolver still returns the old one.
Making changes apply faster
The only way is to prepare in advance: lower the record's TTL to around 300 seconds a day before the move, wait for the old long-TTL answer to age out of caches, and only then change the record. Put the TTL back afterwards — a permanently low value costs extra queries and extra latency for nothing.
When the answers really differ
Two answers where one is the previous value is ordinary caching: wait out the TTL. If they differ without a recent change, check that every authoritative NS for the domain serves the same zone — a mismatch there means a zone transfer that never arrived or an edit made on one server by hand.
Frequently asked questions
- How long does a DNS record take to update?
- As long as its TTL, typically anywhere from 300 seconds to 24 hours. The clock starts when a given resolver last fetched the old answer, not when you made the change.
- Why does the site load the old way for me but the new way for a colleague?
- You are using different resolvers, and their caches expire at different moments. Your operating system and browser keep caches of their own, which sometimes have to be flushed separately.
- Which resolvers are queried?
- Cloudflare (1.1.1.1), Google (8.8.8.8), Quad9 (9.9.9.9), OpenDNS, AdGuard and Yandex. All are anycast networks with points of presence in many countries, so the result reflects more than one region.
- Can I check any record type this way?
- A, AAAA, MX, TXT, NS, CNAME, SOA and CAA are available. Site moves usually mean A and AAAA, mail means MX and TXT, and changing registrar or DNS host means NS.