SSL Checker
Check SSL/TLS certificate details for any domain. Verify expiry, issuer, SANs, and security strength instantly.
Last updated: June 13, 2026
SSL Grading
Get an A+ to F security grade based on protocol version, key strength, certificate chain, and header configuration.
Live TLS Handshake
We connect directly to your server to fetch the raw certificate data — no cached or stale information.
Security Headers
Full audit of 10+ security headers including HSTS, CSP, X-Frame-Options, Permissions-Policy, and CORS policies.
Instant Analysis
Certificate details, fingerprints, SANs, warnings, and recommendations in a single comprehensive report.
SSL Checker — No Uploads Required
Ensure your websites and APIs are secure with our comprehensive SSL Checker tool. Instantly validate SSL/TLS certificates for any domain and get detailed information including certificate issuer, subject, validity period, Subject Alternative Names (SANs), certificate chain depth, TLS protocol version, and cipher suite. The tool warns you about expiring certificates, expired certificates, and self-signed certificates that browsers will flag as untrusted. Whether you're a system administrator monitoring certificate health, a developer debugging HTTPS issues, or a security auditor verifying certificate compliance, our tool provides the real-time certificate inspection you need.
Why This Tool Exists
What makes this useful — and why I built it this way.
Instant Security Audit: Get a complete SSL health check with grade, headers, and warnings in under 2 seconds.
Proactive Monitoring: Catch expiring certificates and missing security headers before they cause service disruptions.
Compliance Ready: Generate downloadable reports for SOC 2, ISO 27001, and internal security audits.
When You'd Use This
Real situations where this tool saves the day.
DevOps Monitoring: Regularly check certificate expiry dates and TLS configuration for production domains and APIs.
Security Audits: Verify that HTTP security headers meet organizational policies and compliance standards.
Vendor Assessment: Evaluate the SSL/TLS security posture of third-party services, APIs, and partner integrations.
Using SSL Checker
It's straightforward — here's how it works.
Enter the domain name (e.g., google.com) in the search field.
Click 'Check SSL' to initiate a live TLS handshake and HTTP header scan.
Review the security grade, certificate details, fingerprints, and security headers audit.
Expand the warnings section for actionable recommendations.
Download or copy the full report for documentation or compliance.
Questions People Ask
Honest answers about how this works.
What information does an SSL certificate contain?
An SSL certificate contains the domain name (CN), the issuing Certificate Authority, validity dates, Subject Alternative Names (SANs), public key, and the certificate chain linking back to a trusted root.
Why is checking SANs important?
Subject Alternative Names (SANs) list all domains and subdomains the certificate covers. If your domain isn't listed in the SANs, browsers will show a security warning even if the main CN matches.
What is a self-signed certificate?
A self-signed certificate is one where the issuer and subject are the same entity. These certificates are not trusted by browsers and should only be used in development or internal environments.
How often should I check my SSL certificate?
It is recommended to monitor your SSL certificates at least monthly, and more frequently (weekly) as certificates approach their expiry date (within 30 days) to avoid unexpected lapses in security.
How is the security grade calculated?
Great question. The grade is a composite score based on TLS protocol version (TLS 1.3 is best), key size (2048+ bits), certificate chain completeness, days until expiry, self-signed status, and the presence of critical HTTP security headers like HSTS, CSP, and X-Frame-Options.
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