LibreWolf

LibreWolf is a fork of Firefox with telemetry removed and privacy settings hardened out of the box, rather than left to be configured.

It disables data collection, strips default search suggestions, enables strong tracking protection and clears cookies on close — the configuration a privacy-focused user would otherwise assemble manually.

The trade-off is that hardened defaults break some sites, and you may need to relax settings per site. Updates also lag slightly behind upstream Firefox releases.