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SOA Record Lookup

soa-lookup

Check zone authority configuration and serial data for DNS operations.

Enter a target and run the tool.

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About SOA Lookup

The SOA (Start of Authority) record is the metadata record that defines a DNS zone. Every zone has exactly one SOA, and it carries critical operational values: the primary nameserver hostname, the responsible party email, the zone serial number (which secondaries use to detect changes), the refresh interval (how often secondaries check for updates), the retry interval (how long to wait after a failed refresh), the expire timer (how long secondaries continue serving stale data if they cannot reach the primary), and the negative-cache minimum TTL (how long resolvers cache "this name does not exist" responses). Our free SOA lookup tool queries the live DNS and returns the full SOA record so you can verify the right primary nameserver is in charge, confirm the serial number incremented after a recent zone edit, or audit refresh and TTL values that affect propagation behavior. This is essential when running a hidden-master DNS setup, troubleshooting zone-transfer issues between primary and secondary servers, or validating that a registrar move did not leave an old zone in place. Free, runs in your browser via DNS-over-HTTPS, no signup required.

Common use cases

  • Verify the serial number incremented after a zone edit.
  • Confirm the primary nameserver listed in the SOA matches your intended hidden master.
  • Audit refresh, retry, and expire intervals for replication health.
  • Check the negative-caching TTL when troubleshooting NXDOMAIN behavior.
  • Read the responsible-party contact for a foreign domain you need to coordinate with.

How to use this tool

  1. Enter the domain whose zone authority you want to inspect (for example, example.com).
  2. Click "Lookup" to query the live SOA record.
  3. Read the primary nameserver, responsible party, and serial number returned.
  4. Inspect the refresh, retry, expire, and minimum-TTL values to assess zone health.

Frequently asked questions

What is the SOA serial number?

A version counter that increases each time the zone changes. Secondaries compare this against their cached copy to decide whether to pull a fresh transfer.

Why is the responsible-party field formatted oddly?

In SOA records the email is stored with a dot replacing the @ — for example, hostmaster.example.com means [email protected].

What does the minimum TTL field do?

It sets the negative-cache TTL — how long resolvers remember that a name does not exist. It is no longer used as a default positive TTL.

Can a domain have multiple SOA records?

No. Exactly one SOA record exists per zone. Multiple SOAs would be a serious misconfiguration.