Free Domain Security Tools
29 free tools to check your domain's DMARC, SPF, DKIM, SSL, DNSSEC, and more. No signup required.
DMARC Record Checker
Analyze DMARC records and email authentication policies instantly.
Check NowPopularSPF Record Validator
Validate SPF records, check DNS lookup limits, and resolve include chains.
Check NowPopularDKIM Record Verifier
Check DKIM key existence, configuration, and selector validation.
Check NowPopularSSL Certificate Inspector
Analyze SSL/TLS certificates, expiration, and security configuration.
Check NowDNS Health Checker
Full DNS configuration analysis and health scoring.
Check NowPost-Quantum Cryptography Scanner
Assess post-quantum cryptography readiness and migration path.
Check NowEmail Header Analyzer
Parse and analyze email headers for routing, authentication, and delays.
Check NowDomain Blacklist Checker
Check domain and IP reputation against DNS-based blacklists.
Check NowMX Record Lookup
Look up and analyze mail exchange records and mail routing.
Check NowPopularDomain Trust Score
Get an instant composite trust score (0-1000) across 29 security categories.
Check NowSPF Record Flattener
Flatten SPF records by resolving all includes to IP addresses, eliminating DNS lookup limits.
Check NowTyposquatting Detector
Find registered domains that look similar to yours (lookalike / confusable) via typosquatting, homoglyphs, and TLD variations.
Check NowGoogle DMARC Mandate Checker
Check if your domain meets Google's bulk sender DMARC and authentication requirements.
Check NowMicrosoft DMARC Mandate Checker
Check if your domain meets Microsoft's Outlook DMARC enforcement requirements.
Check NowSSL Certificate Decoder
Decode and display SSL/TLS certificate details including subject, SANs, and chain info.
Check NowEmail Deliverability Test
Test email authentication, MX records, blacklist status, and deliverability factors.
Check NowDMARC Record Generator
Build DMARC TXT records with policy selection, reporting, and alignment configuration.
Check NowSPF Record Generator
Build SPF TXT records with a visual mechanism builder, lookup counter, and validation.
Check NowDKIM Record Generator
Create DKIM DNS records with selector naming, key type selection, and record formatting.
Check NowDNS Propagation Checker
Check DNS record propagation across multiple global resolvers in real time.
Check NowIPv6 Compatibility Checker
Check if your domain supports IPv6 DNS resolution (AAAA records).
Check NowSubdomain Discovery Scanner
Discover subdomains and check their DNS configuration.
Check NowMTA-STS Policy Checker
Verify your MTA-STS policy for secure email transport.
Check NowBIMI Record Checker
Check your BIMI (Brand Indicators for Message Identification) setup.
Check NowDANE/TLSA Record Checker
Verify DANE TLSA records for certificate-based authentication.
Check NowCAA Record Checker
Check Certificate Authority Authorization records for your domain.
Check NowHTTP Security Header Checker
Analyze HTTP security headers for best practices compliance.
Check NowWHOIS Domain Lookup
Look up domain registration information and expiry dates.
Check NowReverse DNS (PTR) Lookup
Check reverse DNS PTR records for IP addresses.
Check NowWhy Domain Security Matters
Your domain is the foundation of your digital identity. Every email you send, every page your customers visit, and every API call your partners make relies on DNS, SSL, and email security protocols working correctly. A single misconfiguration can lead to email spoofing, phishing attacks, data interception, or complete service outages.
According to the FBI's Internet Crime Report, business email compromise (BEC) attacks caused over $2.9 billion in losses in a single year. Most of these attacks exploit domains without proper DMARC, SPF, or DKIM configuration. Meanwhile, expired or misconfigured SSL certificates erode customer trust and trigger browser warnings that drive visitors away.
Proactive domain security monitoring is no longer optional. Compliance frameworks like SOC 2, PCI DSS, NIS2, and NIST now require organizations to demonstrate ongoing control over their DNS and email security setup. Regular scanning catches configuration drift, unauthorized changes, and emerging vulnerabilities before they become incidents. These free tools give you instant visibility into your domain's security across every critical category.
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