Real TLS Handshake
Performs an actual TLS connection to your server — not a simulation. Reports the exact protocol version negotiated by the server during the handshake.
TLS Version Check: What It Is, How to Check, and Why It Matters for Security & SEO
TLS (Transport Layer Security) is the cryptographic protocol that protects data in transit between a user's browser and a web server. When you visit a site with HTTPS, TLS is what encrypts the connection. The version of TLS your server uses has significant implications for both security and website performance — making it one of the most important configuration details to verify regularly.
TLS 1.3, the current standard, offers the highest security with a faster one-round-trip handshake and stronger encryption by default. TLS 1.2 remains widely accepted and secure when configured correctly with modern cipher suites. However, TLS 1.1 and TLS 1.0 are officially deprecated — major browsers including Chrome, Firefox, Safari, and Edge have dropped support, and standards bodies such as PCI DSS, NIST, and the IETF mandate their retirement. SSL 3.0 and earlier are critically insecure and exploitable via known attacks like POODLE.
From an SEO perspective, TLS version matters directly. Google's ranking algorithm considers HTTPS as a ranking signal. A site with an expired certificate, a deprecated TLS version, or a weak cipher suite may experience ranking drops or browser "Not Secure" warnings that significantly increase bounce rates. Search engine crawlers like Googlebot also need to successfully negotiate a TLS connection to crawl and index your site — a failed handshake means no crawl, no index, no ranking.
Our free Check TLS Version tool performs a real TLS handshake — not a simulation — with your server and reports the negotiated protocol version, cipher suite, certificate expiry, Subject Alternative Names, public key size, and signature algorithm. It also probes which versions are actively enabled, helping you identify if weak legacy protocols remain unnecessarily open. Use it to verify compliance, catch expiring certificates before they cause outages, and ensure your server is configured to modern security standards.