How to Check a Domain's SSL Certificate

Methods to Verify SSL/TLS Certificates

Checking a website's SSL/TLS certificate helps you verify its authenticity, check for expiration, and ensure the connection is properly secured. There are several ways to inspect SSL certificates.

Method 1: Browser Inspection

The easiest way to check an SSL certificate is through your web browser:

1. Navigate to the website (e.g., https://example.com)
2. Click the padlock icon in the address bar
3. Click "Certificate" or "Connection is secure"
4. View certificate details including issuer, validity, and subject

What to Look For

• Issued To: Should match the domain you're visiting
• Issued By: Should be a recognized Certificate Authority
• Valid From/To: Certificate should be within its validity period
• Certificate Type: DV, OV, or EV based on your needs

Method 2: Online SSL Checker Tools

Online tools provide detailed analysis of SSL configurations:

• Whose.Domains SSL Checker: Quick certificate inspection with detailed results
• SSL Labs Server Test: Comprehensive security grading
• SSL Shopper: Certificate chain verification

Method 3: Command Line

For technical users, OpenSSL provides detailed certificate information:

Common SSL Certificate Issues

• Expired Certificate: Certificate has passed its validity date — needs immediate renewal
• Name Mismatch: Certificate domain doesn't match the URL — possible misconfiguration or phishing
• Untrusted CA: Certificate issued by an unknown or untrusted authority
• Incomplete Chain: Missing intermediate certificates in the chain
• Mixed Content: HTTPS page loading HTTP resources
• Weak Cipher Suites: Server using outdated encryption algorithms
• Self-Signed Certificate: Not issued by a trusted CA — common in development environments

SSL Certificate Security Indicators

• 🟢 Secure: Valid certificate, padlock displayed, HTTPS connection
• 🟡 Warning: Certificate issues like upcoming expiration or mixed content
• 🔴 Not Secure: No certificate, expired, or name mismatch