SOA (Start of Authority) Lookup
Free SOA lookup. Check a domain's Start of Authority record - zone serial, refresh timers and admin contact. Instant DNS lookup, no login required.
About the SOA (Start of Authority) Lookup
This free SOA lookup returns a domain's Start of Authority record, which holds zone administration data: the primary nameserver, the admin contact, the zone serial number, and the refresh and retry timers that control how DNS changes propagate.
The serial number is especially useful - it should increment whenever the zone changes, so you can confirm updates have been published.
Frequently asked questions
What is an SOA record?
The SOA (Start of Authority) record holds administrative information for a DNS zone: primary nameserver, admin email, zone serial number, and timing values for refresh, retry and expiry.
What is the SOA serial number?
A version number for the zone that should increase on every change. Secondary nameservers use it to know when to pull updates. If it did not increment after an edit, the change may not be published.
What is the admin contact in an SOA?
An email address for the zone administrator, written with a dot instead of the @ (e.g. admin.example.com means [email protected]).
Did this check reveal a problem?
Postbox Consultancy Services fixes email deliverability for a living - 500+ clients over 10+ years. Authentication, blacklist recovery, cold email infrastructure and full audits.