IPTools UK

DNS Health Check

Scan a domain for common DNS configuration problems — name servers, SOA timers, apex records, mail server reachability, CAA and DNSSEC — with plain-English results.

About this tool

Most DNS problems are invisible until something breaks — mail stops arriving, a site becomes unreachable from some networks, or a certificate authority refuses to issue a certificate. This tool runs a broad sweep of standard checks against well-established DNS conventions and reports each one clearly, so you can catch issues before they cause an outage.

How to use this tool

  1. Enter a domain name, e.g. example.com.
  2. Select "Run health check". The URL updates with your query, so results can be bookmarked or shared.
  3. Review each result — items marked "Problem" are worth investigating first.
Not a complete audit

This tool checks what is visible through standard recursive DNS queries. It cannot check your authoritative name servers directly, detect zone transfer misconfigurations, or guarantee full DNSSEC chain validity.

Frequently asked questions

What does this tool actually check?
It runs a broad set of standard DNS queries — NS, SOA, A/AAAA, CNAME, MX, TXT (SPF), _dmarc TXT (DMARC), CAA and DS (a DNSSEC signal) — and evaluates the results against well-established DNS best practice (RFC 1912, RFC 2181, RFC 2182). It does not attempt a zone transfer or contact your authoritative servers directly; every query goes through Cloudflare's public recursive resolver, the same one used elsewhere on this site.
I got a "warning" — is my domain broken?
Not necessarily. Warnings flag configurations that deviate from best practice (e.g. only one name server, or a low TTL) but often still work fine. "Problem" (fail) results indicate something is more likely to cause real issues, such as an MX record that doesn't resolve.
Does this replace the Email DNS Checker?
No — this tool includes a summary SPF/DMARC check as part of a wider sweep, but the Email DNS Checker goes further, including DKIM (with a selector) and more detailed explanations specific to email authentication.

DNS Lookup

Query A, AAAA, CNAME, MX, TXT, NS, SOA and CAA records for any domain using DNS-over-HTTPS, with full TTL and record detail.

Email DNS Check

Check a domain’s MX, SPF and DMARC records, and DKIM for a given selector, with plain-English explanations of common misconfigurations.

WHOIS Lookup

Look up registration data for a domain, IPv4/IPv6 address or ASN using RDAP, the structured successor to legacy WHOIS.