openssl s_client

Test TLS connections

low risk

interactive breakdown — edit the command and press Explain
$ 
⚠ Risks & cautions
What it does

Connects to a TLS server and shows the chain.

Examples
openssl s_client -connect example.com:443 -servername example.com </dev/nullShow chain · explain & risk-check →
Related
openssl x509
Open the full explainer →More in Users, Permissions & Security

Reference text is hand-written and may be incomplete — check man openssl for your version. Test destructive commands on a non-production system first.