All tools

The full health check: 25+ tests with score, diagnosis and prescription.

Query any DNS record live: A, AAAA, MX, TXT, DS, DNSKEY and more.

Has your DNS update propagated? Compare answers across 5 public resolvers.

Check via RDAP whether a domain is still available.

Check MX, reverse DNS and port availability of your mail servers.

Build a valid SPF record with lookup counter and RFC warnings.

DMARC policy from p=none to p=reject, every option explained.

Define which certificate authorities may issue for your domain.

Generate the TXT record and policy file for enforced TLS delivery.

Inspect the DKIM key for a domain and selector, including key length.

The DS and DNSKEY chain made visible: signed, valid or broken?

Decode email headers: delivery path, SPF/DKIM/DMARC results. Runs entirely in your browser.

Convert internationalized domains to punycode and back.

All checks as a JSON API plus an embeddable score badge.