DNS Propagation Checker

DNS Propagation Checker

When you change a DNS record — pointing a domain at a new server, swapping email providers, or rotating verification TXT entries — the update does not reach the rest of the internet at the same speed. Every recursive resolver caches answers for the length of the record’s TTL, so users on different networks can see different values for hours after a change. The DNS Propagation Checker queries the same hostname against multiple major public DNS resolvers in parallel and shows you exactly which ones have picked up the new answer and which are still serving the stale cached value.

How to Use

1. Enter the hostname you want to check, such as example.com or mail.example.com. Leave off the protocol; the tool strips it automatically.
2. Pick the record type you want to verify — A and AAAA for web hosts, MX for mail servers, CNAME for aliases, TXT for SPF and verification strings, NS for nameserver delegation.
3. Click Check Propagation. The tool fires a DNS-over-HTTPS query to each resolver in parallel from your browser.
4. Review the table: each row shows the resolver IP, the provider, whether its answer matches the consensus, the resolved value, and the remaining TTL on the cached record.
5. If you see Differs on any row, that resolver is still holding the old answer in its cache. Wait for the TTL to expire and re-run the check.

Features

• Multi-resolver query — Checks Cloudflare 1.1.1.1, Google 8.8.8.8, Quad9 9.9.9.9, and AdGuard DNS in parallel, so you see the spread of cached answers in a single click.
• Consensus highlighting — The tool compares the answer sets across resolvers and flags any that disagree with the majority, so propagation gaps jump out instead of hiding in a wall of identical-looking rows.
• Remaining TTL per resolver — Each row shows the cached TTL countdown, telling you roughly how long until that resolver re-queries the authoritative nameservers and picks up your new record.
• All major record types — Supports A, AAAA, MX, CNAME, TXT, and NS lookups, covering web, email, alias, verification, and delegation use cases.
• Runs in your browser — All queries are sent over HTTPS directly from your browser to the resolvers’ public DoH endpoints. No server-side proxy, no logged requests on our side.
• Clear error reporting — Resolvers that return NXDOMAIN, SERVFAIL, REFUSED, or no answer at all are surfaced with explicit status labels instead of silent failures.