DNS Tools

SOA Record Lookup

Look up a domain's SOA (Start of Authority) record.

Enter a domain to look up its SOA record.

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JustChecker tracks your DNS records continuously and alerts you the moment something changes.

What Is an SOA Record?

The SOA (Start of Authority) record holds administrative details about a DNS zone: the primary nameserver, the administrator's contact, a serial number, and timers that control how secondary nameservers and resolvers refresh and cache the zone.

When to Use It

To confirm a zone change was published (the serial number usually increases).
When troubleshooting secondary DNS or zone transfers.
To check negative caching - how long "record not found" answers are cached.

How to Use It

Enter the domain.
Review the primary nameserver, serial and timer values.

Understanding the Result

The admin email is written with a dot instead of @ (for example hostmaster.example.com). The minimum/negative TTL controls how long resolvers remember that a record does not exist - if it is high, a newly added record can take a while to appear.

Limitations

Many managed DNS providers set SOA values automatically. For a full view of all records use DNS Lookup.

Frequently Asked Questions

The SOA ("Start of Authority") record is mandatory for every DNS zone - it identifies the primary authoritative nameserver, the zone administrator's contact, and the timing values that govern how the zone is replicated and cached.

It's a version number for the DNS zone, incremented every time any record in the zone changes - secondary nameservers compare this number to know whether they need to fetch an updated copy of the zone.

It tells secondary (backup) nameservers how often to check the primary nameserver for updates - a shorter refresh interval means changes propagate to secondaries faster, at the cost of more frequent checks.

If a secondary nameserver can't reach the primary for longer than the expire time, it stops answering queries for that zone entirely, treating its data as too stale to be trustworthy - a safeguard against serving badly outdated DNS data.

It sets the default caching time for negative responses (queries for records that don't exist) across the zone, and historically served as the zone-wide default TTL for any record that didn't specify its own.

It's mainly useful for diagnosing DNS propagation and secondary-nameserver-sync issues - if the serial number reported by different nameservers for your domain doesn't match, that indicates your zone hasn't fully propagated to every server yet.

It's formatted as an email address (with the "@" replaced by a dot, per the DNS specification) representing the zone administrator's contact - many providers now use a generic placeholder here rather than a monitored inbox.