Thought it would be nice to compile a list of the web and command line SSL/TLS tools and tests folks use themselves
I’ll start, besides SSL Labs online test https://www.ssllabs.com/ssltest/, I bundled alot of my tools in a Docker container made specifically for testing HTTP/2 and nghttp2 client/tool. However, it contains other tools useful for SSL testing like testssl, cipherscan, ssllabs-scan cli cmd tool etc.
The tools from Cloudflares seem to be primarily about HTTP/2 and not about TLS. The only thing a bit related to TLS I could find is OpenSSL they mention there. (and they do not even use it for checking the HTTPS connection).
https://sslping.com/ is another useful service. Especially for LE certs it can warn you in the last moment if renewing fails, but it also checks your ciphers and similar stuff.