Waterfox

Waterfox began as a 64-bit optimized fork of Firefox and has evolved into a privacy-first alternative that strips out telemetry, data collection, sponsored content, and Pocket integration. Based on Firefox ESR, it ships with DNS over Oblivious HTTP on by default, which Waterfox calls Ultra Protection: DNS queries pass through a Waterfox relay to Cloudflare's resolver, hiding both the content and origin of your requests—a feature no other mainstream browser turns on by default for free.

Privacy goes beyond DNS. Container tabs are on by default, as they now are in Firefox itself since version 153, Private Tabs let you browse anonymously within the same window, and there are no remote experiments or personalization feeds. When Mozilla announced plans to make Firefox an "AI browser," Waterfox's creator Alex Kontos responded with a firm "Waterfox will not include LLMs. Full stop."—making it a deliberate haven for users who want their browser to stay out of the AI race.

Waterfox supports extensions from three ecosystems: Firefox Add-ons (full compatibility), Chrome Web Store, and Opera Web Store (partial compatibility for simpler extensions). Recent versions added native vertical tree-style tabs, tab groups, manual tab unloading, and WebGPU support. The source code is open under the Mozilla Public License and available on GitHub.