DNS

DNS SOA Record Lookup

Zone Authority

Inspect a zone's Start of Authority

We'll query the zone's authoritative nameservers and return the SOA record with every timer decoded.
No zone inspected yet

Enter a domain above to see its primary nameserver, zone contact, serial number, and the refresh, retry, expire and negative-cache timers.

Tool features

Comprehensive SOA record lookup with detailed DNS zone information
4 checks

SOA Record Lookup

Retrieve Start of Authority records for domain authority information

Zone Information

Get primary nameserver, responsible party, and zone configuration details

Fast Resolution

Quick DNS resolution with detailed SOA record analysis

DNS Zone Details

View serial numbers, refresh, retry, expire, and minimum TTL values

What is an SOA record & how it works

How a DNS zone declares its authority

The SOA (Start of Authority) record sits at the top of every DNS zone and declares who is authoritative for it. There is exactly one per zone, and it carries the primary nameserver, the responsible party's email, a serial number, and the timing values that govern how the zone is refreshed across secondary servers.

This lookup reads the SOA record for a domain and breaks out each field — the serial that secondaries watch to detect changes, the refresh/retry/expire intervals, and the minimum TTL used for negative-caching. It's the quickest way to confirm a zone's authority and how quickly changes propagate.

Serial
A version number secondaries compare to detect zone changes; bump it on every edit.
Refresh / Retry
How often secondaries check the primary, and how soon they retry on failure.
Minimum TTL
How long resolvers cache a negative (NXDOMAIN) answer for the zone.

How to use this tool

Check a domain's SOA record in four steps
1
Enter a domain
Type a domain, e.g. example.com — SOA is read at the zone apex.
2
Run the lookup
Click Check SOA Record to fetch the Start of Authority record from DNS.
3
Review the authority
See the primary nameserver, responsible party and serial number for the zone.
4
Check the timers
Inspect the refresh, retry, expire and minimum-TTL values that control propagation.

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Frequently asked questions

Common questions about SOA records
5 Q&A

The SOA (Start of Authority) record is the DNS record at the top of a zone that identifies the primary nameserver, the responsible party's email, the zone serial number, and the timing values for zone transfers.

The serial is a version number for the zone. Secondary nameservers compare it against their copy; when it increases they pull the updated zone. A common convention is YYYYMMDDnn (date plus a daily counter).

Refresh is how often a secondary checks the primary for changes; retry is how soon it tries again after a failed refresh; expire is how long a secondary keeps serving the zone if it cannot reach the primary at all.

The final SOA value sets the negative-caching TTL — how long resolvers remember that a name does not exist (NXDOMAIN) before asking again. Lower values make deletions and fixes propagate faster.

Exactly one. Every DNS zone has a single SOA record at its apex; it is created automatically when the zone is set up and defines the authority for all records beneath it.