Free tools
SSL tools that never take your key.
Decode certificates and CSRs locally, or generate a new self-signed SSL certificate for localhost. These pages are built for searchers who would rather not paste a private key into a random website.
Live SSL checker
Issuer, expiry, SANs, and hostname match for a public site.
SSL certificate decoder
Read a PEM .crt locally — subject, dates, fingerprint.
CSR decoder
Inspect a certificate signing request before you send it.
PEM / DER / PFX converter
Convert certificate formats in this tab. Keys never upload.
Certificate chain validator
Check the trust path and spot a missing intermediate.
HSTS & security headers checker
See HSTS, CSP, and clickjacking headers on a live site.
Bulk SSL expiry monitor
Check certificate days-left on several public hostnames.
Certificate Transparency lookup
See recently logged public certificates for a domain.
Subdomain finder
List public names from CT logs plus a short DNS guess list.
Web port check + nmap commands
Probe 80/443/8080/8443 on a public host, then copy nmap for the rest.
SSH key generator
Make an RSA or ECDSA key pair in the browser.
OpenSSL command cheat sheet
Copy openssl req / x509 / pkcs12 commands.
Certificate generator
Create self-signed SSL, Root CA, host, mTLS, or CSR files in the browser.