Mullvad browser certainly exists in part to advertise a VPN, but offers more privacy protections than Librewolf. See this response from the mullvad-browser dev

Mullvad browser certainly exists in part to advertise a VPN, but offers more privacy protections than Librewolf. See this response from the mullvad-browser developer on exactly this: > There are two main reasons, one which you preemptively answered: > - the privacy model is about having a same fingerprint per platform for Mullvad Browser users, so you're not uniquely identifiable (which will be the case by following privacy hardening guides) > - it is much easier to recommend to user a browser pre-configured for an optimal privacy: some users will want to tinker, but if you don't have the time or knowledge, it's hard to do the right thing > There are also more differences than "just a fork of Firefox", I encourage you to read the following page which goes more into the details: https://mullvad.net/en/browser/hard-facts https://mullvad.net/en/browser/hard-facts source: https://github.com/mullvad/mullvad-browser/issues/1 https://github.com/mullvad/mullvad-browser/issues/1 A librewolf contributor and arkenfox developer chimes in as well stating that it's no competition that mullvad-browser is more secure here: https://github.com/mullvad/mullvad-browser/issues/1#issuecomment-1495998714 https://github.com/mullvad/mullvad-browser/issues/1#issuecom... So as much as I despise companies putting low effort into software rebrands that offer no value, all the facts point towards that very much not being the case here. Edit: However https://privacytests.org/ https://privacytests.org/ shows mullvad-vpn and librewolf as being very similar wrt privacy.