Does my hostname leave the browser?

Yes. The hostname and port are sent to the DevTools backend, which performs the TLS handshake. No other data is transmitted.

How is the A–F grade calculated?

The score starts at 100 and subtracts points for critical TLS issues. An expired certificate is always graded F.

SSL/TLS Deep Inspector

Grade live TLS handshakes with chain trust, protocol, key strength, and expiry checks

Target

Public hostname or domain — private addresses are blocked.

Hostname

Try an example:

Port

How to Use the SSL/TLS Deep Inspector (A–F Grading)

Run a live TLS handshake from DevTools backend, interpret the A–F grade, and fix chain, expiry, and protocol findings.

Why Your TLS Certificate Chain Breaks (and How to Fix It)

A field guide to 'unable to get local issuer certificate' and friends. What a certificate chain is, why order and intermediates matter, and how to find the broken link in a PEM bundle.

SSL Certificate Checker

Analyze SSL/TLS certificates for any domain, check expiration dates, certificate chains, and security details

SSL Chain Analyzer

Paste a PEM certificate bundle and verify the chain order — find missing intermediates, broken links, expired or not-yet-valid certificates, self-signed roots, and duplicates. All in-browser.

Security Headers Checker

Grade CSP, HSTS, and related HTTP security headers from a live response

DNS Propagation Checker

Compare DNS answers from global public resolvers and see propagation consensus instantly