Advanced TLS Checker
SEOTechTests' own advanced TLS/SSL configuration assessment -- certificate, protocols, cryptography, and configuration findings.
Reads the same underlying TLS signal as the site's SSL/TLS Checker -- this page just shows the full certificate, protocol, and cipher breakdown instead of a single line. This is one independent signal used by the Domain Security Score, and can also be run on its own for any domain.
Based on: RFC 8446 — The Transport Layer Security (TLS) Protocol Version 1.3 · RFC 5246 — The Transport Layer Security (TLS) Protocol Version 1.2 +4 more
About this validation
SEOTechTests' own advanced TLS/SSL configuration assessment: certificate, protocol support, cryptography, and configuration findings, with an optional link to Qualys SSL Labs for an independent second opinion.
- Protocol / standard:
- Reference documentation:
- Rules reviewed:
- Sep 8, 2026
SEOTechTests methodology: Data source: SEOTechTests' own native TLS assessment (the same underlying "ssl_tls" signal as the plain SSL/TLS Checker -- this page adds a full breakdown, not a second scored check). Methodology: SEOTechTests' own evaluation criteria, described on this page and in the linked standards -- NOT a reproduction of Qualys's proprietary SSL Labs grading algorithm. External reference: Qualys SSL Labs' own public SSL Server Test is linked as an independent, separate tool for a second opinion; SEOTechTests does not call the SSL Labs API (see providers/sslLabsProvider.ts for the licensing review) and this is not an "SSL Labs Grade."
Standards and vendor-documented behavior can change. This reflects the source as last reviewed above, not a permanent guarantee.
FAQ
What does the Advanced TLS Checker test?
Certificate validity/expiry/hostname match, which TLS protocol versions the server accepts, the negotiated cipher and key strength, and configuration extras like OCSP stapling and ALPN -- summarized as Critical/Warning/Info findings, with the full raw detail available in Technical details.
Why does SEOTechTests check more than certificate validity?
A certificate can be perfectly valid while the server still accepts obsolete protocols, weak keys, or lacks forward secrecy -- real-world TLS misconfiguration is rarely just about the certificate, so this check evaluates the whole handshake, not only the cert.
What is the difference between this test and Qualys SSL Labs?
This is SEOTechTests' own independently-built assessment using its own criteria, run directly from this site. Qualys SSL Labs is a separate, independent, well-known third-party service with its own proprietary grading methodology -- SEOTechTests links to it for a second opinion but does not use its API or reproduce its grading algorithm.[6]
Does a valid SSL certificate mean a website is secure?
No. TLS configuration is only one part of a domain's overall security posture -- a valid, well-configured certificate says nothing about the site's application code, headers, or content, which this site's other checks assess separately.
Why can two TLS testing tools produce different results?
Different tools use different criteria, test from different network locations, and may check different things (e.g. this tool's exact protocol-support probes vs. another tool's own methodology) -- a difference in results doesn't necessarily mean either tool is wrong, just that they're measuring by different rules.