Ad & Tracker Blocking

Bushido blocks ads and trackers at two levels — network-level via Brave's adblock-rust engine, and page-level via CSS cosmetic hiding. No extensions, no configuration needed.

Network-Level Blocking (adblock-rust)

Bushido embeds adblock-rust, a production-grade Rust content blocking engine. It ships with EasyList and EasyPrivacy — about 140,000 filter rules that cover ad networks, trackers, analytics, and fingerprinting endpoints.

Requests are intercepted at the WebView2 COM level via WebResourceRequestedEventHandler. This catches everything — scripts, images, iframes, XHR, fetch, CSS, fonts, websockets — before the browser even starts the connection. Page JavaScript cannot bypass this.

How it works

1. On first startup, Bushido compiles the bundled filter lists into a binary engine (~400ms)
2. The compiled engine is cached to disk (engine.dat)
3. Every subsequent startup deserializes the cache in ~5ms
4. Each request is checked against the engine — median matching time is 0.041ms

What it blocks

• Ad networks (Google Ads, DoubleClick, Amazon Ads, etc.)
• Trackers (Google Analytics, Facebook Pixel, Hotjar, etc.)
• Fingerprinting endpoints
• Malware domains
• Cryptominer scripts
• Social tracking widgets

Cosmetic Hiding (CSS)

Some ads are served from the same domain as the page content (first-party ads). These can't be blocked at the network level without breaking the site. Bushido hides them with CSS rules injected into every page:

• Google ad containers, Taboola, Outbrain, MGID
• Sponsored content sections
• YouTube ad renderers
• Reddit promoted posts
• Newsletter popups, notification prompts
• Ad network containers (Mediavine, Ezoic, Freestar, AdThrive, etc.)

About 150 CSS selectors cover the most common ad containers across the web.

Privacy Features

The same content script also handles:

• WebRTC leak prevention — filters STUN/TURN servers to prevent IP leaks
• Referrer policy — sets origin to minimize tracking via referrer headers
• Do Not Track / Global Privacy Control — sets navigator.doNotTrack and navigator.globalPrivacyControl
• Fingerprint resistance — returns empty arrays for navigator.plugins and navigator.mimeTypes
• Battery API blocking — removes navigator.getBattery to prevent battery-based fingerprinting

Per-Site Whitelist

Some sites break when blocking is on. Click the shield icon in the sidebar to toggle the whitelist for that domain. The whitelist persists to disk.

Whitelisted sites skip both network-level blocking and cosmetic hiding.

Toggle On/Off

Settings > Privacy & Security > Ad blocker

When disabled, the adblock engine skips request checking and content_blocker.js stops being injected. Takes effect on new tabs and page loads.

Shield Badge

The shield icon shows a count of blocked requests for the current tab. This count comes directly from the Rust-side COM handler — no JavaScript involved, no delays.