Free SSL Tools

TLS Configuration Generator

Ready-to-paste Nginx or Apache config for Modern, Intermediate, or Old compatibility — based on Mozilla's published guidelines.

SSL/TLS Knowledge Quiz

12 questions on certificates, the handshake, and revocation — instant explanations after each answer.

SSL Health Check

A 10-point self-assessment of your actual setup — check what applies, get a personalized action list for the gaps.

SSL/TLS Word Search

A word search puzzle built from 12 real SSL/TLS terms — click and drag to find them all.

SSL & CSR Decoder

Paste a certificate or CSR and see every field decoded — issuer, validity, SAN list, key size.

CSR Generator

Generate a private key and CSR in your browser. The key never leaves your device.

Key Matcher

Confirm a certificate (or CSR) and a private key are a genuine matching pair.

SSL Converter

Convert between PEM, DER, and PKCS#12 (.pfx/.p12) formats.

RSA Key Converter

Convert an RSA key between PKCS#1 and PKCS#8 format.

SSL Checker

Check the certificate a live server presents — hostname match, chain, expiry.

Bulk SSL Checker

CT Log Search

CA Chain Builder

OCSP Checker

OpenSSL Trace

DCV Readiness Checker

Certificate Chooser

SSL Server Test

The industry-standard deep scan of your server's certificate, protocol support, and configuration, with a letter grade.

SSL Checker

Quick check of a certificate's validity, expiry date, and chain — good for a fast sanity check.

CSR Decoder

Paste a CSR to verify its domain, organization, and key details before submitting it to a CA.

Certificate Decoder

Paste a certificate to read its exact fields — issuer, validity window, and Subject Alternative Names.

Why No Padlock?

Scans a page for the specific mixed-content resources breaking the padlock, with the exact offending URLs.

crt.sh Certificate Search

Search public Certificate Transparency logs for every certificate ever issued for a domain — useful for auditing.