ToolsDNS & domains

TTL checker

See how long a public resolver will keep a domain's records, for one record or the domain's common records at once. Where the zone is signed, it also shows the TTL set in the zone itself.

Queries built and decoded in your browser
Sent via abbott.cloud to the resolver you choose

Check TTLs

How this works

Your browser builds a DNS query for each record to check, asking for DNSSEC signatures too. "Whole domain" asks for the domain's SOA, NS, A, AAAA, MX, TXT, CAA, HTTPS and DNSKEY records, and for www, _dmarc, mta-sts, _mta-sts, _smtp._tls, autodiscover, selector1/selector2/google DKIM keys and default._bimi.
The queries go together to abbott.cloud/api/dns, which forwards them unchanged to the resolver you picked using DNS over HTTPS (RFC 8484).
This page decodes the answers and lists the TTL of each record set, following any alias (CNAME) to the records it points to.
A resolver gives the time left in its cache, which counts down from the TTL set in the zone. Where the zone is signed with DNSSEC, each signature records the zone's own TTL (the "original TTL", RFC 4034 §3.1.4), so this page shows that exact figure too. Otherwise the TTL shown is a lower bound: the zone's setting is that or higher.

What's kept: nothing. The name you check goes in the page's address so you can share the result, but it isn't stored.

Limitations:

DNS can't list every name in a zone, so "Whole domain" checks common names only. Check any other name on its own.
Different resolvers, and different servers inside one resolver, cache separately, so the time left can differ between lookups.

Code: ttl.js (this page), lib/ttl.js (reading TTLs), dnswire.js (packets), net.js (requests).