Compare answers from multiple DNS resolvers after a record change. Check expected values, response times, and reported TTLs on the map. Each result is a sample from a resolver, not confirmation that every user sees the same answer.
Written by Ishan Karunaratne · Last updated:
A DNS answer's TTL describes its cache lifetime in seconds. For example, 300 seconds is five minutes, 3,600 is one hour, and 86,400 is one day. These are example durations, not recommended defaults for every service.
The tool displays TTL information when the service supplies it. A countdown estimates time remaining from an observation; it does not continuously query that resolver. A freshness percentage is a TTL-based indicator, not proof that the answer is correct or newly fetched.
Expiry does not guarantee an immediate refresh. A resolver may fetch again when a later query arrives, prefetch before expiry, or serve stale data during refresh failures under RFC 8767. Always compare record values and request a new check when timing matters.
Recursive resolvers maintain independent caches. Authoritative servers can also disagree while a provider publishes an update or secondaries refresh a zone. A nameserver migration adds parent delegation and, for signed zones, DS-record checks. Confirm the authoritative state before interpreting differing recursive answers as a cache delay.
New records can encounter negative caching: a resolver may retain an earlier NXDOMAIN or no-data answer. RFC 2308 describes how the zone's SOA information controls the negative cache lifetime. Lowering a new record's TTL does not clear an existing negative cache.
Some differences are intentional. Geographic DNS, split DNS, CDNs, and IPv4 versus IPv6 can lead users to different destinations. Public anycast resolver addresses may route checks to different nodes. A map marker describes the configured endpoint location; it is not a measurement of every network in that country.
| Type | What to verify |
|---|---|
| A / AAAA | IPv4 and IPv6 destinations; check both when supported by your service. |
| CNAME | The alias target and the address records it ultimately resolves to. |
| MX | Mail exchanger hostnames, preferences, and their address records. |
| TXT | The exact verification or email-policy value at the correct hostname. |
| NS | Nameservers for the zone; verify the parent delegation separately. |
| SOA | Zone authority and serial information when investigating differing authoritative answers. |
| CAA | Certificate issuance policy at the relevant name and its applicable ancestors. |
Choose a checker by the information you need: resolver endpoints, supported record types, observation times, expected-value matching, and response details. Server counts alone do not measure coverage of your users.
DNS Checker offers streaming results, a resolver map, match filters, and TTL details where returned. Use independent measurements or your users' configured resolvers when an important region or network is missing from the sample. Check current provider documentation before relying on a feature comparison.
If your browser still reaches an old site, investigate its secure DNS settings, VPN, cached connections, and HTTP cache. Recheck both A and AAAA records and the destination server. The browser may be using a resolver that this tool has not queried.
DNS Inspector
Query specific DNS servers for any record type. Useful for checking authoritative nameserver responses directly, before and after changes.
WHOIS Lookup
Check domain registration details including nameservers, registrar, and expiry date. Verify NS record ownership before propagation checks.
SPF Record Checker
Validate your SPF TXT record against RFC 7208. After checking propagation of TXT records, verify the SPF syntax is correct.
Built and maintained alongside this tool. Free, no signup required.