Free domain intelligence tool — WHOIS/RDAP lookups, DNS records, SSL/TLS certificates, email security, security assessments, and more.
DomainCheckr is a comprehensive domain intelligence platform built in PHP. Enter a domain name or IP address and get a complete security and infrastructure analysis in seconds.
Developed by MWBM Partners Ltd (t/a MWservices)
- RDAP-first lookups with WHOIS fallback
- DNS records (A, AAAA, MX, NS, TXT, CNAME)
- Domain availability detection with configurable registrar buttons
- Structured domain summary (registrar, dates, nameservers, expiry countdown)
- Reverse DNS lookup for IP addresses
- Bulk domain lookup with progress indicator and file import
- Domain comparison (side-by-side with export)
- On-demand domain name suggestions for unavailable domains
- Security Score: Aggregated A-F grade from 12 security checks
- SSL/TLS: Certificate info, TLS version audit, cipher suite check
- Certificate Transparency: crt.sh log lookup
- CAA Records: Certificate Authority Authorization
- DANE/TLSA: DNS-based Authentication of Named Entities
- DNSSEC: Validation status
- HTTP Security Headers: Audit with A-F grading (HSTS, CSP, X-Frame-Options, etc.)
- HTTP Redirect Chain: Detection and analysis
- Email Security: SPF, DMARC, DKIM, MTA-STS, BIMI, SMTP STARTTLS
- Threat Intelligence: Google Safe Browsing, VirusTotal, PhishTank, URLhaus, AbuseIPDB, Shodan
- Blocklist Check: Multi-DNSBL (Spamhaus, Barracuda, SpamCop, SORBS, UCEPROTECT, CBL, SpamRATS, Mailspike)
- Domain Age Risk: Flags recently registered domains
- WHOIS Privacy Detection: Identifies privacy proxy services
- Hosting Country Risk: Assessment based on IP geolocation
- IP geolocation (country, city, ISP, AS)
- HTTP/2 and HTTP/3 protocol support detection
- IPv6 readiness check
- DNS resolution and HTTP response time measurement
- Nameserver diversity check (single point of failure detection)
- Reverse IP lookup (shared hosting detection)
- Technology stack detection (CMS, frameworks, CDNs, analytics)
- Robots.txt and sitemap.xml analysis
- DNS propagation checker (Google, Cloudflare, OpenDNS, Quad9)
- Dark mode, light mode, colourblind-safe theme, auto (system preference)
- Multi-language support (English, Spanish, French, German)
- Keyboard shortcuts (press
?for help) - PWA support (offline capable, Add to Home Screen)
- Client-side domain validation with real-time feedback
- Export results as JSON, CSV, or PDF
- Share lookup results via URL
- QR code sharing
- WHOIS diff (cached vs fresh comparison)
- Domain expiry watch list with notifications and ICS calendar export
- Security score history with sparkline visualisation
- Domain portfolio dashboard
- RSS feed for watched domain changes
- Print-friendly stylesheet
- Responsive design with scrollable tabs on mobile
- JSON API (
?format=json) with CORS support - API key authentication with configurable rate limit tiers
- Standard rate limit headers (
X-RateLimit-Limit,X-RateLimit-Remaining,X-RateLimit-Reset) - Domain ownership verification via DNS TXT record
- RSS feed endpoint (
/feed) - OpenAPI 3.0 specification (
/docs) - Webhook notifications for domain changes
- Admin dashboard with usage statistics
- Content Security Policy (CSP)
- CSRF protection on all forms
- Dual rate limiting (per-session + per-IP)
- Input validation and shell injection prevention
- Do Not Track (DNT) support — skips third-party requests when enabled
- WHOIS contact masking option for GDPR compliance
- Clean URLs (no .php extensions exposed)
- Custom
X-Powered-Byheader (hides PHP) - Privacy Policy and Terms of Service included
- WCAG 2.1 AA accessible
- W3C HTML5 validated
- Backend: PHP 8.4+
- Frontend: Bootstrap 5.3, Bootstrap Icons, vanilla JavaScript
- Caching: Redis → Memcached → file-based (15min TTL)
- DNS: PHP
dns_get_record(), systemwhoisanddigcommands - CI/CD: GitHub Actions (auto version bump, changelog, SFTP deploy, PHP lint)
- Testing: PHPUnit
├── web/
│ ├── public_html_beta/ # Active development (beta branch)
│ │ ├── index.php # Main frontend UI
│ │ ├── lookup.php # Backend API endpoint
│ │ ├── admin.php # Admin dashboard
│ │ ├── health.php # Health check endpoint
│ │ ├── docs.php # Swagger API documentation
│ │ ├── privacy.php # Privacy Policy
│ │ ├── terms.php # Terms of Service
│ │ ├── portfolio.php # Domain portfolio dashboard
│ │ ├── feed.php # RSS feed
│ │ ├── monitor.php # Domain monitoring cron script
│ │ ├── manifest.json # PWA manifest
│ │ ├── sw.js # Service worker
│ │ ├── assets/
│ │ │ ├── css/style.css # Styles (4 themes + print)
│ │ │ ├── images/ # Favicons and logos
│ │ │ └── api/openapi.yaml # OpenAPI 3.0 specification
│ │ ├── includes/
│ │ │ ├── config.php # Application configuration
│ │ │ ├── functions.php # Core functions (~2300 lines)
│ │ │ ├── session_config.php # Session/CSRF setup
│ │ │ ├── infoAppVer.php # Version metadata
│ │ │ └── footer.php # Shared footer template
│ │ └── lang/ # i18n (en, es, fr, de)
│ └── public_html/ # Production (main branch)
├── tests/ # PHPUnit tests
├── .github/workflows/ # CI/CD pipelines
└── .claude/ # Claude Code context
Deployment is automated via GitHub Actions:
| Branch | Deploys to | Trigger |
|---|---|---|
beta |
public_html_beta/ |
Push |
main |
public_html/ |
Push |
Workflows: version bump → changelog → minification → SFTP upload.
# Basic lookup (JSON)
curl -X POST "https://beta.whois.mwhost.online/lookup?format=json" \
-d "domain=example.com"
# With API key
curl -X POST "https://beta.whois.mwhost.online/lookup" \
-H "X-API-Key: your-key-here" \
-d "domain=example.com"
# Health check
curl "https://beta.whois.mwhost.online/health"Full API documentation: /docs
- PHP 8.4+
curlextension (recommended for RDAP and external APIs)whoissystem commanddigcommand (for DNSSEC, CAA, DANE/TLSA checks)opensslcommand (for TLS audit)
(C) 2024 MWBM Partners Ltd (t/a MWservices). All Rights Reserved.