SSL/TLS & Security Tools
Grade a site's SSL/TLS setup, generate a CSR and private key for a new certificate, decode an existing certificate, and check HSTS preload eligibility.
Check whether a mail server's IP address is on DNS blacklists, find dangling CNAMEs that allow subdomain takeover, and publish a security.txt so researchers can report issues to you.
7 free security tools
- SSL/TLS CheckerCertificate chain, expiry, protocol and an A+ to F grade
- CSR & Key GeneratorGenerate a CSR and private key to buy an SSL certificate
- Blacklist CheckerDNSBL reputation lookup
- Subdomain TakeoverDangling CNAME detection
- security.txt GeneratorBuild or validate an RFC 9116 security.txt
- Certificate DecoderRead a PEM X.509 certificate's details
- HSTS Preload CheckerCheck HSTS header against preload-list requirements
Guides: Web & Mail Servers
- Nginx as a Load BalancerThe upstream block, balancing methods (round-robin, least_conn, ip_hash, hash), health checks (passive open-source vs active Plus), retries and failover, keepalive to upstreams, and TCP/UDP load balancing.
Checking a whole domain? The Super Scanner runs every DNS, email, website and security check at once and gives one score.