Domain Monitoring
Add a domain and DomainDNSCheck watches its registration, DNS, TLS and email security, then tells you when something meaningful changes — before it becomes an outage.
Free for up to 10 domains per account. The public tools never need an account.
What is watched
The signals that break websites and mail when they change unexpectedly.
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Registration
Registrar, expiry date, EPP status codes (hold, transfer lock, pending delete) and the nameservers at the registry.
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DNS
A, AAAA, NS, MX and CAA records, important TXT records such as SPF and site verification, and the DNSSEC state.
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Website & TLS
HTTPS availability, where the site finally redirects to, and the certificate’s expiry, trust and hostname match.
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Email security
SPF and DMARC presence and strength, mail servers (MX), MTA-STS and TLS-RPT.
How monitoring works
- You add a domain. DomainDNSCheck validates it and records a baseline of every watched signal.
- The baseline does not send alerts, except a clearly labelled warning if something is already urgent, such as an expired certificate.
- Each scheduled check compares the new results with the previous ones in a normalised form, so a different record order is never reported as a change.
- Meaningful changes and new problems are emailed once; when a problem returns to normal it is marked resolved.
Alerts without noise
Every alert is deduplicated: an unchanged warning is not repeated on every check. Expiry reminders are sent at fixed steps — 30, 14, 7, 3 and 1 days before a certificate expires, and from 60 days before the domain registration ends. You can turn alerts or resolution emails off per domain or for the whole account.
“Check failed” is not “domain changed”
Registries, resolvers and websites sometimes time out. When a check cannot complete, DomainDNSCheck records the failure, keeps the last known good values and retries later. A provider failure never produces a false “your DNS disappeared” alert; a website is reported unreachable only after repeated confirmations.
An alert looks like this
Nameservers changed for example.com
- Previous
- ns1.oldprovider.net
ns2.oldprovider.net - Current
- aria.ns.cloudflare.com
mark.ns.cloudflare.com - Detected
- 26 Sep 2026, 08:42 UTC
Check frequency
- Daily
- Every 12 hours
- Every 6 hours
Checks run from a shared scheduler and are spread across the hour, so the exact time varies by a few minutes.
Your list stays private
Monitored domains belong to your account and are never published, shared or given public URLs. Detailed check snapshots are kept for 30 days and the change history for 365 days. Deleting your account deletes everything.