DNS Lookup — Global Propagation Check

Queries 12 major public DNS resolvers around the world at once, so you can see whether a DNS change has actually propagated globally or is still cached on some resolvers — the exact question you're asking right after you change nameservers, update an A record, or fix an MX record and want to know if it's actually live yet.

A note on how this actually queries each resolver

Every resolver here is queried using standard DNS-over-HTTPS wire format (RFC 8484) rather than each provider's own proprietary JSON API — that format is what every genuine DoH service actually supports, unlike the "JSON DoH" convenience APIs that only a handful of providers ever implemented (Quad9 retired theirs in 2025; several others never had one). But running in a browser adds a second constraint on top of that: the resolver also has to send CORS headers, or the browser silently blocks the response even though the request went through fine. Most public DoH resolvers are built for OS or app-level use, not for being called directly from a web page's JavaScript, so they don't bother. The 12 resolvers listed here are well-documented public DoH services chosen for that reason, favouring their neutral or security-only endpoints over content-filtered ones so a filter policy doesn't masquerade as a propagation mismatch.

Why one lookup from your machine doesn't answer that question

DNS records get cached by resolvers for the duration of their TTL. Change a record and different resolvers around the world will pick up the new value at different times, based on when they last cached it. Querying from just your own machine only tells you what your resolver currently has cached — it says nothing about whether a user on a different ISP, in a different country, is still getting the old answer. Querying multiple resolvers at once actually answers the propagation question instead of guessing at it.

The record types you'll be checking most often

• A — IPv4 address, far and away the most common lookup
• AAAA — IPv6 address
• MX — which mail servers handle the domain's email, and in what priority order
• CNAME — an alias pointing one name at another
• TXT — free-text records, doing heavy lifting for SPF, DKIM, DMARC and domain verification
• NS — the authoritative nameservers for the domain
• SOA — zone metadata, including the serial number that tells secondary servers whether the zone has changed
• CAA — which certificate authorities are allowed to issue certs for the domain

If you know a change is going out, dropping the TTL to something short (like 300 seconds) 24 hours ahead of time shrinks this whole propagation window — worth doing as routine practice before any planned DNS cutover, not something to remember only after the fact.