Firefox ships with several privacy tools you might not know about. Here's what each one does and when it matters.
Enhanced Tracking Protection (ETP)
Settings → Privacy & Security → Enhanced Tracking Protection.
Three modes:
- Standard: Blocks known trackers in private windows + some third-party cookies. Good default.
- Strict: Also blocks cross-site tracking in normal windows, fingerprinting, cryptominers. May break some sites.
- Custom: Pick exactly what to block.
What "tracking" means: Firefox uses a list from Disconnect.me to identify known tracking domains. ETP blocks network requests to those domains.
What it doesn't stop: First-party tracking (the site you're on tracking you), behavioral analysis, or trackers on domains not in the list.
Total Cookie Protection
Included with ETP Strict. Firefox creates a separate "cookie jar" for each website you visit. Cookies set by a tracker on site-a.com can't be read when you visit site-b.com.
This makes cross-site tracking via cookies effectively impossible for sites using separate domains. The core cross-site tracking mechanism — "this cookie was set by tracker.com on many sites and we can link your visits" — is broken.
Limitation: Doesn't stop same-domain tracking (first-party cookies used by large platforms that own many sites) or fingerprinting.
Firefox Monitor (Breach Detection)
monitor.firefox.com or about:logins → "Check for Breaches"
Firefox Monitor checks your email addresses against the Have I Been Pwned database. It:
- Tells you which breaches your email appears in
- Lists what data was exposed per breach
- Sends email alerts when new breaches include your email
Free, no subscription needed. Requires signing in with Firefox Account for continuous monitoring.
Pocket and Privacy
Firefox bundles Pocket for article saving. Pocket is Mozilla-owned. If you use Pocket, your saved article list lives on Mozilla's servers.
If you don't use Pocket and prefer no third-party services: disable it via about:config → extensions.pocket.enabled = false.
Firefox Suggest (Address Bar)
Firefox Suggest shows contextual suggestions in the address bar based on your query — including sponsored suggestions from advertising partners.
Disable sponsored suggestions: Settings → Privacy & Security → Address Bar → uncheck "Contextual suggestions" and "Suggestions from sponsors."
Or keep contextual suggestions (which can be genuinely helpful) but disable only the sponsored ones.
about:config Privacy Tweaks That Actually Matter
network.http.referer.XOriginPolicy = 2 — Only send the Referer header to same-origin sites. Prevents sites from knowing which website you came from when clicking cross-origin links.
dom.battery.enabled = false — Battery API can be used for fingerprinting. Disabling prevents this.
media.peerconnection.ice.no_host = true — Hides your LAN IP address from WebRTC requests. Important when using a VPN.
dom.enable_user_timing = false — Removes high-resolution timing APIs that enable timing-based fingerprinting. May slow down some performance measurements on sites.
Container Usage for Privacy
Containers are the practical privacy feature most users miss. Each container has isolated cookies and localStorage.
Privacy use cases:
- Social media container: Facebook/Twitter stay isolated, can't track you on other sites
- Shopping container: Amazon's tracking cookies stay contained
- Work container: Keep work login sessions separate from personal
Install: Multi-Account Containers (Mozilla extension, free).
VPN Integration
Firefox for Android and desktop has optional Mozilla VPN integration (paid service). If you use Mozilla VPN, Firefox respects the VPN tunnel.
For third-party VPNs: they work at the OS level, so all Firefox traffic goes through them automatically. No special integration needed.
Network Throttling for Privacy Research
Testing how much data your browser leaks: DevTools → Network tab → throttle network → observe what requests go out and to which domains on a cold page load.
Useful for: verifying whether a site loads third-party trackers, checking if an extension makes unexpected network requests.
Summary: Privacy Stack for Firefox
For most users, this combination is strong:
- ETP Strict (Settings → Privacy → Enhanced Tracking Protection)
- uBlock Origin (AMO — free, open source, blocks more than ETP alone)
- Multi-Account Containers (AMO — isolates social media)
- DNS over HTTPS (Settings → Privacy → DNS over HTTPS, use NextDNS)
- HTTPS-Only mode (Settings → Privacy → HTTPS-Only Mode)
That's it. Anything beyond this has rapidly diminishing returns and increasing site-breakage risk.
The most impactful single change: ETP Strict mode + uBlock Origin. Together they block the vast majority of tracking that most users encounter day-to-day. Everything else is refinement.
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