HTTPS-Only Mode
Also known as: https everywhere
A browser setting that upgrades all requests to HTTPS and warns when only HTTP is available.
Modern browsers can be configured to refuse plain-HTTP navigation, automatically upgrading URLs and showing a warning when no HTTPS version exists. This replaces the older EFF 'HTTPS Everywhere' extension.
Enabling HTTPS-Only Mode is one of the lowest-effort, highest-value privacy steps for any browser.