SSL Certificate Checker

Check SSL/TLS certificate validity, expiration, issuer, and protocol for any domain. Free, instant.

What is SSL/TLS?

SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) are cryptographic protocols that secure communications over the internet. An SSL certificate authenticates a website's identity and enables encrypted connections. Monitoring certificate expiration is critical to avoid downtime and security warnings.

SSL Check API

Check SSL certificates programmatically:

curl "https://api.fengdeagents.site/api/ssl?host=example.com" \
  -H "X-API-Key: YOUR_KEY"

Get a free API key · View all tools