Find security risks hiding in your domain — before attackers do.
DomainPreflight is a free, browser-based suite of domain security and email authentication tools. No signup. No backend. Nothing leaves your browser.
| Tool | What it does |
|---|---|
| DNS Preflight | SPF, DKIM, DMARC, PTR, IP reputation — full pre-send audit |
| Email Deliverability | IP blacklist checks, AbuseIPDB reputation, email header analyzer |
| WHOIS / Expiry | Domain expiry countdown, registrar info, risk tiers |
| Dangling Records | Subdomain takeover detection via certificate transparency logs |
| Typosquat Monitor | Lookalike domain detection with live DNS resolution |
| DMARC Report Analyzer | Paste XML aggregate reports — get visual breakdown instantly |
| DNS Propagation | Check propagation across 5 resolvers in real time |
Most tools are reactive — you use them when email is already bouncing or a subdomain has already been taken over.
DomainPreflight is the proactive check:
- Dangling Records — browser-based subdomain takeover detection. No CLI, no Python install. Pulls from cert logs + can-i-take-over-xyz fingerprints.
- Typosquat Monitor — browser version of dnstwist. Generates lookalikes, checks which ones resolve live.
- Alignment Engine — detects provider-specific DMARC alignment failures for 10 ESPs including SendGrid, Mailgun, Microsoft 365, Google Workspace.
- Copy-paste fixes — every audit ships the exact DNS record to paste. Not just a grade.
- Vanilla HTML/CSS/JS — zero frameworks
- DNS-over-HTTPS (Cloudflare DoH)
- Cloudflare Worker for IP reputation proxy
- No backend, no database, no tracking
- Deployed on Vercel
git clone https://github.com/metriclogic26/domain-preflight.git
cd domain-preflight
python3 -m http.server 3000| Suite | What it does |
|---|---|
| ConfigClarity.dev | Server & DevOps audit tools |
| DomainPreflight.dev | Domain security & email authentication |
| PackageFix.dev | Dependency vulnerability scanner |
MIT © MetricLogic — the moat is the live data fetch, not the code.