SSL / TLS check:Will your visitors see a browser security warning?

• HTTPS connection

  Checks the site is served over HTTPS, so browsers don't label it "Not secure" and visits stay private.

• HTTP to HTTPS redirect

  Checks that old http:// links and typed addresses land on the encrypted https:// page.

• HSTS header

  Checks the header that keeps return visits on HTTPS, so they never start on interceptable plain HTTP.

• HSTS preload readiness

  Checks your HSTS header qualifies for the browsers' built-in HTTPS-only list.

• Minimum TLS version

  Checks the server refuses old TLS 1.0 and 1.1, which attackers can use to weaken a connection.

• Certificate expiry

  Shows how many days your TLS certificate has left, before browsers show a full-page warning.

• Certificate chain

  Checks browsers can verify who issued your certificate, so visitors don't see a privacy warning.

• Mixed content

  Finds files loaded over http:// on an HTTPS page, which browsers block or mark as not secure.

How it works

1. 1

   Check HTTPS

   We check that the site is served over HTTPS and that http:// addresses redirect to it, and whether HSTS is set.

2. 2

   Run a TLS handshake

   A TLS handshake against the host checks the certificate chain, the days left before expiry, and whether TLS 1.0 or 1.1 are still accepted.

3. 3

   Look for mixed content

   The page is checked for any image, script or other resource that still loads over plain HTTP.

This is a practical check of certificate, chain, expiry and protocol versions, not a full cipher-suite audit like SSL Labs.