Browser Hygiene

Your browser is the front line of exposure. It handles cookies, executes scripts, loads ads, and reveals details about your system. Even with strong network security, poor browser hygiene can leak your identity or activity. This chapter covers how to configure your browser for safer use.

5.1 Why Browser Hygiene Matters

Websites and advertisers use multiple techniques to track you:

Cookies: Small files that persist across sessions.
Fingerprinting: Collecting details like screen resolution, fonts, and plugins to identify you.
IP leakage: Revealing your true IP via WebRTC or DNS.
History & cache: Retaining traces of visited sites.

A hardened browser helps minimize these risks.

5.2 Best Browsers for Privacy

Tor Browser

Best anonymity: Routes all traffic through Tor.
Built-in protections: Blocks fingerprinting, forces HTTPS, isolates cookies.
When to use: For high-risk sessions where anonymity is crucial.

Firefox (Hardened)

Flexible and open-source.
Supports privacy extensions and custom configuration.
Needs manual hardening (see appendix below).

Chromium-based browsers (Brave, Ungoogled Chromium)

Brave: Built-in ad/tracker blocking, Tor window option.
Ungoogled Chromium: Minimal Google integration.
Caution: Avoid Chrome or Edge — too tightly tied to data collection.

5.3 Essential Settings

In your chosen privacy browser, adjust these:

Disable WebRTC (prevents IP leaks).
Block third-party cookies (isolates trackers).
Force HTTPS-only mode (prevents insecure requests).
Clear history on exit (removes session traces).
Set search engine to a privacy-friendly option (DuckDuckGo, Startpage, Searx).

5.4 Recommended Extensions

uBlock Origin: Blocks ads, trackers, and malicious domains.
HTTPS Everywhere (often built-in now): Forces HTTPS connections.
NoScript / uMatrix: Advanced script and request control (power users only).
Cookie AutoDelete: Clears cookies after tabs close.
Decentraleyes: Prevents requests to centralized CDNs.

Tip: Don’t overload your browser with extensions. Each one adds fingerprinting surface.

5.5 Private Browsing Habits

Use a separate browser profile (or dedicated browser) for adult browsing.
Never log into personal accounts on this browser.
Regularly clear cache, cookies, and site data.
Avoid installing unnecessary plugins or extensions.

5.6 Common Mistakes

Using the same browser for everything: Leads to cross-contamination of cookies and identities.
Trusting Incognito Mode: It hides history locally but not from ISPs, employers, or trackers.
Leaving JavaScript unrestricted: Increases fingerprinting risk.

5.7 Summary

The browser is often the weakest link in privacy setups.
Tor Browser offers the strongest protections but is slower.
Hardened Firefox or Brave is suitable for daily use.
Key hygiene steps: block trackers, disable leaks, and isolate sessions.
Good habits matter as much as tools.

Appendix: Firefox Hardening (about:config)

⚠️ Warning: These tweaks improve privacy but may break some websites. Apply gradually and test.

Fingerprinting Protection
- privacy.resistFingerprinting → true
- webgl.disabled → true
- dom.battery.enabled → false
- media.peerconnection.enabled → false (disables WebRTC leaks)
Cookie & Storage Control
- privacy.firstparty.isolate → true (isolate cookies per site)
- network.cookie.cookieBehavior → 1 (block third-party cookies)
- privacy.clearOnShutdown.cookies → true
Network & DNS
- network.dns.disablePrefetch → true
- network.prefetch-next → false
- network.trr.mode → 3 (forces DNS over HTTPS, if desired)
History & Telemetry
- places.history.enabled → false (disable history)
- datareporting.healthreport.uploadEnabled → false
- toolkit.telemetry.enabled → false
- browser.safebrowsing.malware.enabled → false
- browser.safebrowsing.phishing.enabled → false
  (turning these off removes Google checks but increases risk — weigh carefully)

Next chapter: Malware Prevention — protecting yourself from malicious downloads, pop-ups, and scripts.