SSL Certificate & Security Checker
Check SSL validity, HTTPS enforcement, and security headers for any website. Get an instant security grade. Free, no sign-up.
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Frequently Asked Questions
- What does the security grade mean?
- A = SSL valid + HTTPS redirect + most security headers present. F = SSL is invalid or broken. Grades in between reflect partial security header coverage.
- Can this check certificate expiry dates?
- The tool confirms whether the SSL certificate is valid (browser would trust it). Exact expiry dates require a TLS inspection library — use a dedicated SSL monitoring service for expiry alerts.
- What is HSTS?
- HTTP Strict Transport Security tells browsers to only connect via HTTPS for a specified period. Without it, attackers can downgrade connections to unencrypted HTTP.
- Is this tool free?
- Yes, 100% free. Checks run via Cloudflare edge, no data is stored or logged.
- Why might SSL show as invalid?
- The certificate may be expired, self-signed, for a different domain, or have a broken certificate chain. The tool reports the error message from the server.