Because f*ck Chrome and Chromium-based browsers.
Privacy-centric, open-source browser with unique UI features like vertical tabs, Split View, and Zen Glance, focusing on security and tranquility.
Currently my favorite web browser. It's fast and very customizable. It supports workspaces, vertical tabs, side panels, and it even has a nice compact mode.
The Tor software protects you by bouncing your communications around a distributed network of relays run by volunteers all around the world: it prevents somebody watching your Internet connection from learning what sites you visit, it prevents the sites you visit from learning...
To access
Tor.
This project is a custom and independent version of Firefox, with the primary goals of privacy, security and user freedom.
The most private web browser (after
Tor Browser of course).
Open-source web browser built on Firefox, prioritizing privacy and anonymity while offering a Chromium-like interface, user customization, and robust tracking protection.
Even more customizable than
Zen Browser, but I encountered several annoying bugs, which is why I prefer using Zen.
A Floorp fork with custom branding and KDE patches by OpenSUSE. Features include pre-installed extensions like Ublock Origin and canvasblocker.
Especially nice if you're using Linux with
KDE Plasma because it integrates nicely with the global menu.
Waterfox is an open-source, privacy-focused browser based on the popular open source browser with a red panda as a mascot. It is designed to be a drop-in replacement for said browser that offers enhanced privacy features, performance improvements, and customizability while...
Used it a long time ago, so not sure if it's any good today.
The Mullvad Browser is a privacy-focused web browser developed in a collaboration between Mullvad VPN and the Tor Project. It’s designed to minimize tracking and fingerprinting. You could say it’s a Tor Browser to use without the Tor Network.
Private web browser. Especially useful if you're using
Mullvad VPN VPN.
An open-source web browser forked from Mozilla Firefox. It focuses on security, efficiency, customization, and no data gathering.
Pretty old web browser that's still regularly updated.
This is a privacy oriented and deblobbed web browser based on 
Mozilla Firefox technology. It enables many features upstreamed by the Tor Uplift project using preferences from the arkenfox-user.js project.
For using Firefox on your Android phone.
Browser using the Gecko layout engine to render web pages, which implements current and anticipated web standards.
Another option for Android users.
Comments
Good list. You should also add Midori.
Thanks for putting together this list!