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DomainHealth

Domain Health Checker

Run a comprehensive health check across DNS, email authentication, TLS, security headers, registration, reputation and uptime — in seconds.
https://
DNS Records
SSL Certificate
WHOIS
Security Headers
Blacklists

Tool features

DNS, security, performance and email in one read-only audit
6 checks

DNS configuration

A, AAAA, MX, NS, TXT and CAA records, plus DNSSEC, checked for gaps and misconfiguration.

Email authentication

SPF, DKIM, DMARC, MTA-STS, TLS-RPT and BIMI in one pass.

SSL/TLS & headers

Certificate validity and expiry, legacy protocol support and HTTP security headers.

Performance

Time to first byte, HTTP/2 and HTTP/3, CDN detection and compression.

Reputation & registration

Blocklist status, registration expiry, redirects and canonical host.

Graded, exportable report

One A+ to F grade with per-category results, exportable as a PDF.

What is a domain health report & how it works

Everything that keeps a domain online, trusted and fast

A domain health report is a complete, read-only audit of a domain graded from A+ to F. In a single scan it checks DNS configuration, email authentication, the SSL/TLS certificate, HTTP security headers, domain registration and DNSSEC, performance, blacklist reputation, and redirects and canonicalization.

Problems in any of these areas cause outages, lost email, browser warnings or slow pages, and they often go unnoticed until something breaks. The report highlights the issues that matter most and how to fix them. It is free, needs no signup, and you can export the full report as a PDF.

Read-only
The scan only queries public DNS, HTTP and TLS endpoints; nothing is changed.
Category score
Each area is graded separately, then weighted into the overall grade.
Dedicated tools
Every category links to a specialised checker for a deeper look.

How to use this tool

Audit a domain in four steps
1
Enter a domain
Enter the domain name you want to audit (for example, example.com).
2
Run the health check
Click “Run health check” to scan DNS, SSL/TLS, security headers, performance, reputation and email authentication.
3
Read the grade
Review the overall A+–F grade and the per-category results in the report.
4
Dig deeper and export
Open a category’s dedicated tool (SSL Checker, DNS Lookup, Security Headers and more) for a deeper analysis, then export the full report as a PDF.

Domain Health Checker — Frequently Asked Questions

Common questions about domain health reports
7 Q&A

A domain health report is a consolidated audit of a domain's DNS configuration, SSL/TLS certificate, HTTP security headers, domain registration, performance, blacklist reputation, redirects and email authentication. ShowDNS combines all of these into a single graded report so you can see a domain's overall health at a glance.

Yes. The domain health report is completely free to use, requires no signup, and you can run it on any public domain as many times as you need.

It covers 8 areas: DNS configuration (A, AAAA, MX, NS, TXT, CAA), email authentication (SPF, DKIM, DMARC, MTA-STS, TLS-RPT, BIMI), the SSL/TLS certificate, HTTP security headers, domain registration and DNSSEC, performance (TTFB, HTTP/2, HTTP/3, CDN, compression), blacklist and reputation, and redirects and canonicalization.

Every check is scored as pass, warning, or fail. Passing checks earn full points, warnings earn half, and failures earn none. The combined score maps to a letter grade from A+ (95+) down to F (below 60), giving you a single measure of domain health.

Yes. The Email Authentication section validates SPF, DKIM and DMARC records, and also checks DMARC alignment, MTA-STS, TLS-RPT and BIMI so you can confirm your domain is protected against spoofing and has strong deliverability.

Yes. After running a report, click “Export PDF” to download a print-ready report sheet that includes the overall grade, a summary of passing, warning and failing checks, and the detailed findings for every category.

No. The domain health checker is completely read-only. It only performs standard DNS, HTTP and TLS lookups to evaluate the domain and never modifies any records or settings.