Free Tool — 25+ Checks — No Account Required

Domain Diagnostics

One input. Every check. Inspect DNS records, email authentication, network infrastructure, and security posture from a single interface. The all-in-one toolkit for agencies, MSPs, and IT teams who need fast answers.

Select a check above and enter a domain to begin
25+
Diagnostic Checks
3
DNS Resolvers
100%
Free — No Limits
<1s
Average Query Time
Capabilities
One Tool to Diagnose Everything
Stop jumping between 5 different websites. Domain Diagnostics gives you DNS, email authentication, network, and security checks in a single interface with educational guidance at every step.

25+ Check Types

MX, A, AAAA, CNAME, TXT, NS, SOA, CAA, PTR, SRV, SPF, DKIM, DMARC, BIMI, MTA-STS, TLS-RPT, WHOIS, HTTP, HTTPS, and more — all from one input.

Smart Tool Routing

Checks like Blacklist and DMARC deep-analysis automatically route to dedicated TheBRHub tools with your query pre-filled. Zero friction.

Built-In Education

Every tile, every record, every value has a hover tooltip that explains what it is, why it matters, and what to do about it. Built for all skill levels.

Copy & Export

One-click copy on every record. Export full results as a text report for client tickets, documentation, or internal audits.

Client-Side Privacy

All DNS queries use DNS-over-HTTPS directly from your browser. No data passes through TheBRHub servers. Complete privacy by design.

Ecosystem Integration

Results link directly to Blacklist Intelligence, DMARC Analyzer, Email Security Analyzer, and Bounce Analyzer with domain pre-filled.

FAQ
Frequently Asked Questions
Everything you need to know about Domain Diagnostics.
Domain Diagnostics runs entirely in your browser using DNS-over-HTTPS — no data touches our servers. Every check includes educational hover tooltips that explain what each record means and why it matters. And for deep analysis (blacklists, DMARC, full email security), results link directly to our dedicated TheBRHub tools with your query pre-filled.
Tiles with a cyan left border are "redirect" checks — they'll take your input and route you to a dedicated TheBRHub tool that handles that check in depth. For example, clicking "Blacklist" will redirect you to Blacklist Intelligence with your domain/IP pre-filled and auto-started. This gives you the best of both worlds: quick access from one interface, deep analysis from purpose-built tools.
Yes. Most DNS checks work with domain names, but checks like PTR (reverse DNS), Blacklist, and network checks accept IP addresses. The tool will validate your input and run the appropriate query.
No limits. All checks are free and unlimited. Since queries run client-side via DNS-over-HTTPS, there's no server-side rate limiting from TheBRHub. The only limits are what the public DNS resolvers (Google, Cloudflare, Quad9) impose, which are extremely generous for normal use.
Go Deeper
Dedicated TheBRHub Analysis Tools
Domain Diagnostics gives you the quick answer. These tools give you the deep dive.

Blacklist Intelligence

Scan 80+ DNS-based blacklists for IP and domain listings.

Open Tool

Email Security Analyzer

Full SPF, DKIM, DMARC, MTA-STS, BIMI, and TLS-RPT audit.

Open Tool

DMARC Analyzer

Deep-dive into DMARC policy, alignment, and enforcement status.

Open Tool

Need Expert Help With Your Results?

Our deliverability team can diagnose and fix DNS, authentication, and infrastructure issues for you.

Schedule Free Consultation
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