SSLchk.sh

Certificate toolkit

Everything here runs in your browser. Certificates, requests and private keys never leave this device.

Paste one certificate or a whole chain. DER and PKCS#7 files can be opened or dropped here too.

About SSLchk.sh

SSLchk.sh is a free tool published by DigitalFyre. It connects to a public HTTPS site the way a browser does and grades its certificate, chain of trust, TLS versions and security headers from A+ to F.

Certificates are verified against the Mozilla root store. HSTS preload status comes from hstspreload.org.

Privacy

SSLchk.sh does not store the hostnames you check. A report is held in memory for 2 minutes, so a repeat request answers at once, and is then discarded. It sets no cookies and loads no third-party scripts or fonts.

The certificate toolkit runs entirely in your browser. Certificates, requests and private keys never leave your device.