SOA Record Lookup
Check SOA (start of authority) records for any DNS zone across 12 global resolvers. Free real-time DNS checker.
What is an SOA record?
An SOA record ("start of authority") sits at the apex of every DNS zone and carries metadata about the zone: the primary nameserver, the responsible-party email, and a set of timing parameters (serial, refresh, retry, expire, minimum TTL). Every DNS zone has exactly one SOA.
When to check the SOA
- Diagnosing whether a zone change has actually been published (the SOA serial typically increments on each change)
- Confirming which nameserver is currently the primary
- Auditing zone-wide TTL and refresh settings
FAQ
What does the SOA serial number mean?
It's a version counter for the zone. By convention it's a date-style integer (YYYYMMDDNN), incremented every time the zone changes. Secondary nameservers compare serials to decide whether to pull a fresh zone copy from the primary.
Why does the SOA serial differ across resolvers?
The newest serial is what the primary nameserver actually has. Resolvers may serve a slightly older serial until their cache (governed by the SOA's minimum-TTL field) refreshes.
All record-type lookups
WhereIsDNS has dedicated pages for each common DNS record type. Each one defaults the tool to that record type and includes background on what the record means and what to look for.
- A Record Lookup — IPv4 addresses for a hostname
- AAAA Record Lookup — IPv6 addresses for a hostname
- CNAME Lookup — Aliases pointing one hostname to another
- MX Record Lookup — Mail servers for a domain (with priorities)
- NS Record Lookup — Authoritative nameservers for a domain
- TXT Record Lookup — SPF, DKIM, DMARC, and other text records
- CAA Record Lookup — Which CAs may issue certs for the domain
- PTR (Reverse DNS) Lookup — Reverse DNS — IP back to a hostname
- Home (defaults to A records)