Sorry to jump in here, but Vivaldi does phone home to its sync services. There are also some Google services, especially on install, that do phone home. More details here: vivaldi.com/blog/decoding-network-activity-in-vivaldi With regard to privacy, usually Viv gets dinged from a fingerprinting standpoint. This is adjustable, but it is true that it is _less_ anonymous than something like Mullvad by default.