As others pointed out, you can set it up to always upgrade to HTTPS and warn you when it's not supported. But that's not gonna work all the time: some websites

As others pointed out, you can set it up to always upgrade to HTTPS and warn you when it's not supported. But that's not gonna work all the time: some websites will have self-signed certificates (which is better that nothing I guess), some will return 403 or 404 (for HTTPS only), some will just not load after trying for half a minute.