You can check if you are using TLS 1.3 in Firefox by going into the about:config page and checking the value of the security.tls.version.max setting. If it is set to 4, then you are using TLS 1.3.

Catalin Cimpanu is the Security News Editor for Bleeping Computer, where he covers topics such as malware, breaches, vulnerabilities, exploits, hacking news, the Dark Web, and a few more.