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
Enter a URL and see issuer, validity, SANs, expiry, and hostname match.
SSL certificate decoder
Read subject, issuer, SANs, dates, and fingerprints from a .crt PEM.
CSR decoder
Check a certificate signing request before you send it to a CA.
OpenSSL command cheat sheet
Copy openssl req / x509 / pkcs12 commands for localhost and CSRs.
Certificate generator
Create self-signed SSL, Root CA, host, mTLS, or CSR files in the browser.