Waterfox is a Firefox fork built in London by developer Alex Kontos since 2011. It strips out the telemetry, sponsored content, and data collection that Firefox ships with, then adds privacy features on top. The result is a browser that works like Firefox but sends nothing back about how you use it.

Telemetry is not just turned off. It is removed at build time, so there is no switch to accidentally flip. The browser includes Oblivious DNS by default, which hides both what you are looking up and who is asking from the DNS resolver. It also ships with uBlock Origin pre-installed for ad and tracker blocking out of the box.

Container tabs let you isolate different browsing contexts (work, personal, shopping) so cookies and tracking data do not cross over between them. You can also open individual private tabs without switching to a full private window. Waterfox supports Firefox extensions, plus Chrome and Opera extensions through compatibility layers.

Worth knowing

Waterfox was acquired by System1, a US advertising company, in December 2019. That raised real concerns in the privacy community. In July 2023, founder Alex Kontos bought it back and the project is fully independent again under BrowserWorks Ltd. The team is small (under 5 people), which means security patches sometimes arrive later than Firefox releases. There is no iOS version. If you use Waterfox Sync, your data goes through Mozilla's servers in encrypted form.