SSL Certificate Checker
Analyze SSL/TLS certificate security with comprehensive validation and security grading
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Start Checking Certificates
Enter any domain to analyze its SSL certificate security and configuration
How to Use SSL Certificate Checker
- 1
Enter Domain Name
Type the domain name you want to analyze into the input field. You can enter any publicly accessible domain like example.com, github.com, or your own website domain.
Tip:Don't include 'https://' or 'www.' - just the domain name like 'example.com'. - 2
Review Security Grade
Check the overall security grade (A-F) that summarizes the certificate's security posture based on industry standards including expiration, key strength, and modern security features.
Tip:Aim for grade A or B - anything below requires attention to security vulnerabilities. - 3
Analyze Security Checks
Examine each security check result with pass/warn/fail status. This includes certificate expiry, key strength, signature algorithms, TLS versions, OCSP stapling, and HSTS headers.
Tip:Red failures need immediate action, yellow warnings suggest improvements, green passes indicate good security. - 4
Study Certificate Details
Review comprehensive certificate information including subject and issuer details, validity periods, technical specifications, and Subject Alternative Names (SANs) coverage.
Tip:Pay attention to expiration dates and ensure all your domains are covered in the SAN list. - 5
Plan Security Improvements
Use the analysis results to identify and prioritize security improvements like certificate renewal, TLS version upgrades, enabling HSTS headers, or implementing OCSP stapling.
Tip:Set up monitoring alerts for certificate expiration at least 30 days before expiry.
Features & Benefits
Complete Certificate Analysis
Comprehensive examination of SSL/TLS certificates including chain validation, expiration dates, key strength, and signature algorithms with detailed technical information.
Security Grade Assessment
Industry-standard security scoring (A-F) based on certificate strength, encryption standards, and security best practices with clear pass/warn/fail indicators.
TLS Protocol Detection
Identifies supported TLS versions, cipher suites, and protocol negotiations to ensure modern encryption standards are being used for secure connections.
OCSP & HSTS Validation
Checks for OCSP stapling implementation and HSTS header presence to verify advanced security features that improve performance and prevent attacks.
Expiration Monitoring
Calculates days until certificate expiration with color-coded warnings to help prevent unexpected certificate expiry and service disruptions.
Multi-Domain Coverage
Displays all domains covered by Subject Alternative Names (SANs) to verify complete certificate coverage for websites with multiple domains or subdomains.
Frequently Asked Questions
What information can this tool provide about SSL certificates?
The tool provides comprehensive certificate analysis including subject and issuer details, validity periods, key strength, signature algorithms, TLS version support, OCSP stapling status, HSTS headers, and Subject Alternative Names. It also generates security grades and specific recommendations for improvements.
How accurate are the security grades and recommendations?
Security grades are based on industry standards from organizations like NIST and OWASP. The tool evaluates key size, signature algorithms, TLS versions, and security headers using the same criteria employed by security professionals and compliance frameworks.
Can this tool check certificates for internal or private domains?
The tool is designed for publicly accessible domains with valid SSL certificates. It cannot analyze certificates for internal networks, localhost, or domains not accessible from the public internet due to security and network limitations.
What should I do if my certificate receives a failing grade?
Failing grades typically indicate critical issues like expired certificates, weak encryption, or outdated protocols. Immediately renew expired certificates, upgrade to stronger key sizes (2048+ bits), enable TLS 1.2 or 1.3, and implement security headers like HSTS.
How often should I check my SSL certificates?
Check certificates monthly for routine monitoring and immediately after any infrastructure changes. Set up automated monitoring to alert you 30-60 days before expiration. Critical production systems should have continuous certificate monitoring in place.
What are Subject Alternative Names and why are they important?
Subject Alternative Names (SANs) list all domains and subdomains covered by a single certificate. They're crucial for multi-domain websites and ensure all your domains are properly secured. Missing domains in SANs can cause browser security warnings.
Technical Specifications
Use Cases & Applications
HTTPS Setup Debugging
Troubleshoot SSL/TLS configuration issues during website deployment, identify certificate chain problems, and verify proper HTTPS implementation.
Security Compliance Auditing
Perform security assessments for compliance requirements, validate encryption standards, and ensure certificates meet organizational security policies.
Certificate Renewal Planning
Monitor certificate expiration dates across multiple domains, plan renewal schedules, and prevent unexpected certificate expiry disruptions.
Vendor Security Verification
Assess third-party service security posture by analyzing their SSL certificates, TLS configurations, and security best practice implementation.
Performance Optimization Analysis
Identify certificate-related performance issues, verify OCSP stapling implementation, and optimize TLS handshake efficiency for faster loading.
Incident Response Investigation
Investigate security incidents involving certificate issues, analyze certificate chains during breaches, and verify remediation effectiveness.