Browsers mostly don't check whether a HTTPS certificate has been revoked so maybe you'd like to do it manually. There are a few ways how to query an Online Certificate Status Protocol (OCSP) server so let's see some of them. You'll need a browser (and the
Microsoft, Google, Apple & Mozilla announced yesterday that they're removing TLS 1.0 and TLS 1.1 protocols from Internet Explorer, Edge, Chrome, Safari & Firefox browsers in the
beginning middle of 2020. Your visitors most probably don't use them already so you can disable them in your server configs today. But let's verify that first using the “Handshake Simulation” tool available in the SSL Labs Server Test.