Anti-Tracking Guide

How Brave randomises fingerprints (farbling)

Brave's farbling alters canvas, WebGL, audio and user agent output per site and per session, so fingerprints do not match across sites. From Brave's 2020 post.

Official source: Brave, Fingerprinting defenses 2.0. Verified on

1 min read · Review scheduled for 2027-01-20

Contents

In short

  • Idea: instead of blocking features, Brave subtly alters their output so the result is hard to use as an identifier and does not break normal use (Brave).
  • Seed: each site's values come from a seed tied to its domain and a random token that Brave creates at startup.
  • Effect: a site sees the same values during one browsing session, different sites see different values, and a new session gives new ones.
  • Features touched: canvas, WebGL, MediaDevices, plugins, Web Audio, the user agent string and WebXR support, according to the post.

Why per-site matters

A tracker that sits on many sites wants to recognise you on all of them. If each site gets different values, the mixes seen on two sites do not match, so the tracker cannot join them by fingerprint alone. If values never changed (as with a plain fingerprint), they would match everywhere. That is the reasoning behind seeds tied to the domain.

Limits

  • The post is from 18 May 2020. Brave has published newer posts on specific areas, such as language and GPU fingerprinting, but we did not read them, so we do not state current behaviour.
  • Randomising is not the same as blocking. A site can still read the other details of your browser.
  • We did not test Brave.

Keep reading: Firefox protections · Safari · Compared

Outside this page: How well farbling holds up against new fingerprinting methods is not something the Brave post settles.