DNS Propagation Checker

Network Server-side dns propagation resolver nslookup domain google cloudflare opendns quad9

This tool processes your data on the server: whatever you submit here is sent over the network to be processed, then the result is sent back to your browser.

What it does

After changing a DNS record, it can take a while before every resolver around the world sees the new value — this is called DNS propagation. This tool queries several major public DNS resolvers in parallel (Google, Cloudflare, OpenDNS, Quad9, and others of your choosing) and shows you exactly what each one currently returns for a domain, so you can tell at a glance whether propagation is complete or still in progress, or whether one resolver is stuck on a stale/cached answer.

Try it

How it works

You pick a domain, a record type, and which public DNS resolvers to query (plus any custom resolver IP you want to add).
Your browser sends this list to /api/tools/dns-propagation-checker.
The server (tools/dns-propagation-checker/server.js) creates one dedicated dns.Resolver instance per selected server address, points each at its resolver with setServers(), and fires all the queries in parallel with Promise.allSettled — so one slow or unreachable resolver doesn't hold up the others.
Each resolver's raw answer (or error) is returned and displayed in its own row, so you can visually compare them.

Reading the results

All resolvers agree → the record has fully propagated.
Some resolvers show the old value, others the new one → propagation is still in progress; wait out the record's TTL and check again.
One resolver errors out or times out → that resolver may be unreachable from the server, overloaded, or filtering/blocking the domain.
A resolver returns a different IP than the others for the same record (with no old/new pattern) → often normal for domains behind a CDN/Geo-DNS setup, since different resolvers are treated as being in different network locations.

Notes

Each resolver is queried directly by the server hosting PiliBox — not by your own computer — so results reflect propagation as seen from the server's network location.
TTL values are shown next to A/AAAA records when available, which helps estimate how long it'll take for a change to fully propagate.
Up to 10 resolvers can be queried in a single request.