Free SSL Checker
FreeFree ssl checker — instantly check security configuration for any domain or email. Protect your domain reputation. No signup required.
Frequently Asked Questions
What does the SSL Checker verify?
The SSL Checker validates the complete SSL/TLS configuration for any domain, including: certificate validity period and expiration date, certificate issuer and chain of trust, SANs (Subject Alternative Names) the certificate covers, TLS protocol version support (TLS 1.2 / 1.3), and cipher suite security. An expired or misconfigured SSL certificate causes browser warnings, blocks HTTPS traffic, and can affect email sending via STARTTLS.
How do I check my SSL certificate expiry date?
Enter your domain in the SSL Checker and the tool instantly shows the exact expiration date of your SSL certificate. Most certificates are valid for 90 days (Let's Encrypt) or 1-2 years (paid CAs). Set up renewal reminders at least 30 days before expiry. Certificate expiration causes immediate browser security warnings and service outages — automated renewal via certbot or similar tools is strongly recommended.
What is an SSL certificate chain error?
An SSL chain error occurs when an intermediate certificate is missing or not properly installed on the web server. SSL certificates are issued by a chain: Root CA → Intermediate CA → End-entity (your domain). If the intermediate certificate is absent, some browsers and email clients cannot verify trust back to a trusted root CA and will show security warnings. The SSL Checker shows the full chain and flags any gaps.
Is the SSL Checker tool free to use?
Yes. The SSL Checker is completely free on FreeMailTools.com with no registration required. We offer 200+ free email security, validation, DNS, and deliverability tools for developers, sysadmins, and security researchers.