SSL Certificate Checker
Analyze SSL/TLS certificates for any website. Check expiration dates, validation, certificate chain, and security configuration.
What is SSL Certificate Checker?
An SSL Certificate Checker is a security analysis tool that examines and validates SSL/TLS certificates for any website. It retrieves certificate information, analyzes security configurations, and provides detailed insights about encryption status, validity periods, and potential security vulnerabilities.
Who uses this tool: Web developers, system administrators, security professionals, website owners, compliance officers, and IT teams responsible for maintaining secure web communications.
How to Use This Tool
- Enter Domain: Type the domain name (without http:// or https://) in the input field
- Submit Check: Click the "Check SSL" button to initiate the certificate analysis
- Review Summary: Examine the certificate validity status and expiration information
- Analyze Details: Expand sections to view certificate chain, security details, and technical specifications
- Follow Recommendations: Review security recommendations and implement suggested improvements
Example:
Input: github.com
Output: Valid certificate issued by DigiCert, expires in 180 days, strong encryption (RSA 2048-bit), secure TLS 1.3 protocol support
- Certificate Chain: Examine the complete trust chain from server certificate to root CA
- Subject Alternative Names: Review all domains covered by the certificate
- Cryptographic Details: Analyze signature algorithms, key sizes, and cipher suites
- Export Certificate: Copy the PEM-formatted certificate for offline analysis
Use Case:
Security audits often require detailed certificate analysis to ensure compliance with organizational security policies and industry standards.
Understanding SSL Certificate Results
Valid Certificate (Green Check)
The certificate is properly signed, within its validity period, and issued by a trusted Certificate Authority. The domain matches the certificate's subject or SAN entries.
Expiring Soon (Yellow Warning)
The certificate is currently valid but will expire within 30 days. You should renew the certificate soon to avoid service disruption.
Invalid/Expired Certificate (Red X)
The certificate has expired, is not yet valid, uses weak cryptography, or has other security issues. Immediate action required to maintain secure connections.
- Key Size
- RSA keys should be at least 2048 bits; 4096 bits preferred. ECDSA keys should be at least 256 bits.
- Signature Algorithm
- SHA-256 or SHA-384 are secure. SHA-1 is deprecated and considered insecure.
- Protocol Support
- TLS 1.2 and 1.3 are secure. TLS 1.0/1.1 and SSL protocols should be disabled.
- Certificate Authority
- Trusted CAs are recognized by major browsers. Self-signed certificates trigger security warnings.
Common Use Cases
Security Audits
Verify SSL/TLS configuration compliance with security policies, check certificate validity, and identify potential vulnerabilities in web applications.
Certificate Monitoring
Track certificate expiration dates to prevent service outages and maintain continuous secure connections for critical web services.
Troubleshooting SSL Issues
Diagnose browser security warnings, certificate chain problems, and connection errors to resolve SSL-related website issues.
Compliance Verification
Ensure websites meet industry standards (PCI DSS, HIPAA, SOX) that require proper SSL/TLS implementation for data protection.
Third-Party Assessment
Analyze external websites, API endpoints, and partner services to verify their security configurations before integration.
Learning and Training
Educational tool for understanding SSL/TLS concepts, certificate structures, and web security best practices.
Technical Details
- SSL Handshake Simulation: Initiates a secure connection to the target server to retrieve the certificate
- Certificate Parsing: Extracts and decodes certificate fields including subject, issuer, validity dates, and extensions
- Chain Validation: Verifies the complete certificate chain from server certificate to trusted root CA
- Cryptographic Analysis: Examines key algorithms, signature methods, and encryption strength
- Security Assessment: Compares configuration against current security best practices and standards
Network Dependencies
Results depend on network connectivity and may fail for servers behind firewalls or those requiring client certificates for access.
Point-in-Time Analysis
Certificate information reflects the current configuration and may change after certificate renewal or server reconfiguration.
Server Configuration Scope
Analysis focuses on the presented certificate and may not detect all server-side security configurations or vulnerabilities.
Certificate Privacy
Certificate information is publicly accessible and does not reveal sensitive data. However, certificates may contain organizational information visible to anyone.
Analysis Accuracy
Tool provides general security guidance but should not replace professional security assessments for critical systems. Always verify recommendations with security experts.