Free SSL Certificate Checker

What does this tool check?

Our free SSL checker analyzes your website's SSL/TLS certificate and provides:

• Certificate expiration date and time remaining
• Color-coded status indicator (Green/Blue/Yellow/Orange/Red)
• Certificate issuer and validity status
• TLS version and certificate fingerprint
• Clear renewal recommendations

Note: This tool focuses on certificate expiration monitoring only. For comprehensive security testing (TLS versions, cipher suites, vulnerabilities), use SSL Labs.

Why check your SSL certificate?

Expired SSL certificates cause browser warnings that drive visitors away, hurt your SEO rankings, and expose sensitive data. Regular checking helps you renew certificates before they expire, preventing downtime and security issues.

How does the status indicator work?

We use color-coded indicators aligned with ACME/Certbot renewal standards (renew at 1/3 life remaining):

For auto-renewing certificates (90-day Let's Encrypt, 45-day certs, etc.):

• Green (>33% remaining): Healthy, no action needed
• Blue (25-33% remaining): In renewal window, auto-renewal should trigger
• Yellow (15-25% remaining): Should have renewed, check auto-renewal config
• Orange (5-15% remaining): Renewal overdue, investigate immediately
• Red (<5% remaining): Critical, expiring imminently

For manually-renewed certificates (1-year, 2-year, etc.):

• Green (30+ days): Healthy, no action needed
• Blue (14-30 days): Plan renewal
• Yellow (7-14 days): Renew now
• Orange (3-7 days): Urgent, renew immediately
• Red (<3 days): Critical, expiring imminently

How often should I check?

Manual checking is tedious and easy to forget. That's why we built SSLGuard - automatic SSL monitoring with email, Slack, and webhook alerts. Sign up free to monitor up to 3 domains automatically.