SSL Certificate Checker - Inspect TLS Chain, Expiry Date, SANs & Issuer Live
Verify any domain’s live SSL/TLS certificate chain, inspect the issuing Certificate Authority (Let’s Encrypt, Cloudflare, DigiCert), exact expiration date, Subject Alternative Names (SANs), and protocol negotiation in seconds.
This tool sends your input to our server to process it.
Security & servers
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How to use it
Follow these steps in the workspace above.
- Enter the hostname or URL you want to inspect.
- Click Check SSL to perform a live TLS handshake against port 443.
- Review the certificate validity status, days remaining until expiry, issuer details, and hostname coverage.
How it works
An expired, misconfigured, or incomplete SSL/TLS certificate chain immediately blocks visitors with a full-screen browser warning, halts webhook deliveries, and causes Googlebot to drop your pages from search results. With automated 90-day Let’s Encrypt certificates and the industry move toward shorter certificate lifetimes, proactive TLS verification is essential for DevOps and SEO teams.
What Our Live TLS Handshake Inspector Verifies
- Certificate Expiration & Not-Before Window: Confirms the certificate is currently active and calculates exact days remaining so you can catch failed ACME renewals before an outage occurs.
- Subject Alternative Names (SANs): Checks whether both the apex domain and subdomains are covered by the X.509 certificate.
- Intermediate CA Chain Integrity: Desktop browsers sometimes fetch missing intermediate certificates via Authority Information Access (AIA), whereas mobile browsers and API clients fail if the server omits intermediate chain certificates.
After verifying your TLS certificate, check whether your server sends HSTS using our HTTP Security Headers Checker.
