Why it exists
When you change a DNS record you are mostly flying blind. Your own resolver might show the new value while half the planet still sees the old one, and the usual advice ("wait up to 48 hours") tells you nothing about where you actually are in that window. Lookup sites help, but most show a single snapshot in a table. D.PRO instead watches the change converge: it keeps polling and draws the OLD-to-NEW switch region by region until it is done, so you can see progress rather than guess at it.
What it is, and isn't
D.PRO is a read-only observer of public DNS. It runs one session at a time: you start a check, watch it converge, and it stops. It is:
- not authoritative DNS or DNS hosting - it never changes a record, only reads them;
- not a domain registrar;
- not an uptime or alerting service - it does not keep watching after a check finishes or notify you of anything;
- not a guarantee - readings are best-effort snapshots of what public resolvers returned, see the terms.
Who makes it
D.PRO is an independent project with a single maintainer. It is not affiliated with, sponsored by, or endorsed by any DNS provider, domain registrar, or public resolver operator. Cloudflare is named throughout only because it hosts the site and its edge network provides the nine regional query points; the public resolvers listed below are queried over their standard public endpoints, nothing more.
How it's funded
D.PRO is free. There is no paid tier, no account, and no sign-in. Running costs are covered by ads served through Google AdSense. The privacy notice covers what that means for cookies, and what the site itself collects (short version: no first-party analytics; each check's form values, time, and coarse country/city are stored so we can tell real use from automated traffic).
What it measures
When you change a DNS record, resolvers around the world keep serving the previous answer until their cached copy expires (its TTL). D.PRO repeatedly asks public resolvers what they currently return for your record and classifies each answer as OLD, NEW, UNKNOWN (something else), or ERROR (no usable response). The run converges when every region has switched to the new value.
The nine-region vantage
Queries are issued from nine Cloudflare macro-regions: two in North America, plus South America, Western Europe, Central & Eastern Europe, Asia-Pacific, Oceania, Africa, and the Middle East. Each region runs its own lookups from that region's edge, so the map shows real geographic spread rather than one vantage point.
Which resolvers are queried
Each region queries a set of large public resolvers over DNS-over-HTTPS (RFC 8484 wire format):
Cloudflare, Google, Quad9, OpenDNS, AdGuard, DNS.SB and IIJ. Supported record types are
A, AAAA, CNAME, MX, TXT and
NS.
Why a check can be fast or slow
Propagation time is bounded by the record's TTL and by how aggressively each resolver re-queries. A low-TTL A record can converge in seconds; a nameserver change with a day-long TTL at the registry can take much longer. D.PRO polls quickly at first and then backs off, and it stops once the change has fully propagated or the observation window closes.
Contact
Questions, bug reports, or a resolver you think should be in the set: email hello@dnspropagation.pro. It is a small project, so replies are best-effort, but every message is read.