SSL Certificate Checker

Our SSL Certificate Checker is a powerful, free online tool designed to help website owners, system administrators, and security professionals check SSL/TLS certificate status, expiration dates, and security information. SSL certificates are essential for securing websites and protecting user data through encrypted connections.

This tool automatically connects to any domain, retrieves its SSL certificate information, and provides detailed analysis including expiration dates, issuer information, certificate chain validation, security status, and potential issues. Certificate checks are processed securely through our server to retrieve certificate data.

Perfect For:

• Website Owners: Monitor SSL certificate expiration dates to avoid service disruptions. Set up regular checks to ensure certificates are renewed before expiration.
• System Administrators: Check SSL certificate status across multiple domains. Verify certificate validity and identify security issues.
• Security Professionals: Audit SSL certificate configurations for security compliance. Identify weak certificates, expired certificates, or security vulnerabilities.
• DevOps Engineers: Monitor SSL certificates in production environments. Automate certificate expiration alerts and monitoring.
• Compliance Auditors: Verify SSL certificate compliance for security standards (PCI DSS, HIPAA, etc.). Ensure proper certificate configuration.
• Website Developers: Check SSL certificate status during development and testing. Verify certificate installation and configuration.
• E-commerce Sites: Ensure SSL certificates are valid for secure payment processing. Monitor certificate status to maintain trust and security.
• Certificate Monitoring: Set up regular certificate checks to monitor expiration. Receive alerts before certificates expire.

Key Features:

• Certificate Expiration Check: View certificate expiration date and days remaining. Get alerts for certificates expiring soon.
• Validity Status: Check if certificate is valid, expired, or about to expire. Identify certificates that need renewal.
• Issuer Information: View certificate issuer details including Certificate Authority (CA) name and organization.
• Subject Information: View certificate subject details including domain name and organization information.
• Certificate Chain: Analyze certificate chain validation. Check for proper certificate hierarchy.
• Subject Alternative Names (SANs): View all domains and IP addresses covered by the certificate. Identify multi-domain certificates.
• Certificate Fingerprint: View SHA-256 certificate fingerprint for verification and identification.
• Security Analysis: Identify security issues such as weak key sizes, deprecated algorithms, or expired certificates.
• Signature Algorithm: View certificate signature algorithm (RSA, ECDSA, etc.) and key size information.
• Response Time: Measure SSL handshake response time for performance analysis.
• Export Functionality: Copy or download certificate information for documentation and reporting.
• Privacy-First: Certificate checks are processed securely. Your domain is not stored or logged.

SSL Certificate Best Practices:

• Monitor Expiration: Set up monitoring alerts for certificates expiring within 30 days. Renew certificates well before expiration.
• Use Strong Certificates: Use certificates with at least 2048-bit key size. Prefer ECDSA certificates for better performance.
• Keep Certificates Updated: Renew certificates before expiration to avoid service disruptions. Use automated renewal when possible.
• Check Certificate Chain: Ensure proper certificate chain configuration. Include intermediate certificates for proper validation.
• Use SAN Certificates: Use Subject Alternative Names (SANs) for multiple domains. Avoid using multiple single-domain certificates.
• Enable HSTS: Use HTTP Strict Transport Security (HSTS) headers to force HTTPS connections and prevent downgrade attacks.
• Regular Audits: Perform regular SSL certificate audits to identify security issues. Check for weak algorithms or expired certificates.
• Automate Monitoring: Set up automated certificate monitoring and alerts. Use tools to track certificate expiration across domains.

How to Use This SSL Certificate Checker:

1. Enter Domain: Type the domain name you want to check (with or without www). For example: "example.com" or "www.example.com".
2. Select Port: Choose the port number (default is 443 for HTTPS). Use custom ports for non-standard SSL configurations.
3. Click Check: Click "Check Certificate" to retrieve and analyze the SSL certificate information.
4. Review Results: Review the certificate information including expiration date, validity status, issuer, and security analysis.
5. Check Security Issues: Review any security warnings or issues identified in the certificate analysis.
6. Export Information: Copy or download certificate information for documentation or monitoring purposes.

Understanding SSL Certificates:

• What is an SSL Certificate? An SSL (Secure Sockets Layer) certificate is a digital certificate that authenticates a website's identity and enables encrypted connections between a web server and a browser.
• Why Are SSL Certificates Important? SSL certificates are essential for securing online transactions, protecting user data, building trust, and meeting compliance requirements. They enable HTTPS encryption.
• Certificate Expiration: SSL certificates have expiration dates (typically 1-2 years). Expired certificates cause security warnings and connection failures.
• Certificate Types: Common certificate types include Domain Validated (DV), Organization Validated (OV), and Extended Validation (EV) certificates.
• Certificate Authorities: Certificates are issued by Certificate Authorities (CAs) such as Let's Encrypt, DigiCert, GlobalSign, and others.

Use Cases & Examples:

Example 1: Certificate Expiration Monitoring

You manage multiple websites and need to monitor SSL certificate expiration. You use the SSL Certificate Checker to check each domain and discover:

• example.com: Expires in 45 days (needs renewal soon)
• blog.example.com: Expires in 120 days (still valid)
• shop.example.com: Expired 5 days ago (urgent renewal needed)

This helps you prioritize certificate renewals and avoid service disruptions.

Example 2: Security Audit

You're performing a security audit of your website's SSL configuration. You check the certificate and discover:

• Certificate uses 1024-bit key (weak, security issue)
• Uses SHA1 signature algorithm (deprecated)
• Certificate chain is incomplete (missing intermediate certificates)

This audit helps you identify security vulnerabilities and improve your SSL configuration.

Example 3: Multi-Domain Certificate Check

You have a SAN certificate that covers multiple domains. You check the certificate and see:

• Main domain: example.com
• SANs: www.example.com, api.example.com, admin.example.com
• All domains are properly covered by the certificate

This confirms your multi-domain certificate configuration is correct.

Related Tools:

• URL Redirect Checker - Track redirect chains and analyze HTTP responses
• WHOIS Lookup Tool - Retrieve domain ownership and registration information
• Robots.txt Generator - Create and validate robots.txt files
• XML Sitemap Generator - Create XML sitemaps for your website
• .htaccess Generator - Generate Apache configuration files

Frequently Asked Questions

💡 Pro Tip: Set up automated SSL certificate monitoring to receive alerts before certificates expire. Most certificate authorities and hosting providers offer automated renewal services. For Let's Encrypt certificates, use Certbot for automatic renewal. Regular certificate checks help prevent security issues and service disruptions.