Firefox has strong privacy protections built in, but the defaults are a starting point. This guide covers what's enabled by default in 2024, what additional settings help, and which Firefox-specific features set it apart from Chrome.
Built-In Privacy Protections (2024)
Enhanced Tracking Protection (ETP)
Enabled by default in "Standard" mode:
- Blocks known trackers from tracking company lists (Disconnect.me)
- Isolates cookies from social trackers
- Blocks cryptominers and fingerprinters
- Protects against cross-site cookie tracking
To see what's blocked: click the shield icon in the address bar while on any site.
Strict Mode (Settings → Privacy & Security → Enhanced Tracking Protection → Strict):
- Blocks all tracking content, even in non-tracker contexts
- May break some sites (video embeds, login buttons)
- Worth enabling if privacy is a priority
Total Cookie Protection
Firefox's most significant privacy innovation: cookies are partitioned by site. A third-party cookie on site-a.com cannot be read when you visit site-b.com. Prevents cross-site tracking via cookies without blocking cookies entirely.
Enabled by default since Firefox 86.
Firefox Containers (Built-in)
Each container isolates cookies from other containers. Even Total Cookie Protection is enhanced by containers.
HTTPS-Only Mode
Settings → Privacy & Security → HTTPS-Only Mode:
- Upgrades all connections to HTTPS
- Warns before loading HTTP sites
- Firefox tries to find an HTTPS version automatically
Enable for "HTTPS-Only Mode in all windows" for maximum protection.
Essential about:config Settings
about:config offers finer control beyond the Settings UI:
Reduce Fingerprinting
privacy.resistFingerprinting = true
Spoofs many browser fingerprinting vectors: timezone, screen size, locale, user agent, canvas. Side effects: all timezones appear as UTC, reduced screen resolution in canvas.
privacy.fingerprintingProtection = true (Firefox 119+)
More targeted fingerprinting protection with fewer side effects than resistFingerprinting.
DNS over HTTPS
network.trr.mode = 3 (DoH only, fallback disabled)
network.trr.uri = https://mozilla.cloudflare-dns.com/dns-query
Mode 2 (fallback to plain DNS) is the default. Mode 3 is more private.
Telemetry Opt-Out
toolkit.telemetry.enabled = false
browser.ping-centre.telemetry = false
browser.newtabpage.activity-stream.feeds.telemetry = false
browser.newtabpage.activity-stream.telemetry = false
datareporting.healthreport.uploadEnabled = false
WebRTC Privacy
media.peerconnection.ice.default_address_only = true
Prevents WebRTC from leaking local IP addresses (important with VPN).
Referer Header
network.http.referer.XOriginPolicy = 2 (send origin only for cross-origin requests)
network.http.referer.XOriginTrimmingPolicy = 2 (send only scheme+host for cross-origin)
Default sends full referer; these settings reduce information leakage to third parties.
Essential Extensions
uBlock Origin
The most effective ad and tracker blocker. Features Chrome's MV3 cannot support (MV2 stays in Firefox):
- Dynamic filtering: allow/block by domain type
- Cosmetic filtering: remove cookie consent dialogs
- Medium mode: block all third-party scripts by default
- Filter list subscriptions (EasyList, uBlock filters, etc.)
Multi-Account Containers
Isolate browsing contexts. Assign sites to containers permanently. Auto-open Facebook in an isolated "Social" container so it can't track across the web.
Privacy Badger (EFF)
Learns which trackers to block based on behavior rather than blocklists. Complements uBlock Origin.
What Firefox Doesn't Do By Default
For completeness, these require manual configuration:
- Block all third-party cookies: Settings → Privacy → Standard blocks some trackers; Strict blocks more
-
Resist fingerprinting: opt-in via
about:config - HTTPS-only mode: opt-in in Settings
- No telemetry: Settings → Privacy & Security → Firefox Data Collection → uncheck all
Firefox vs. Chrome Privacy
| Feature | Firefox | Chrome |
|---|---|---|
| Total Cookie Protection | ✅ Built-in | ❌ Not equivalent |
| MV3 forced by 2024 | ❌ MV2 still works | ✅ Forces MV3 (limits uBO) |
| DNS over HTTPS | ✅ Cloudflare/NextDNS options | ✅ Google DNS |
| Sync encryption | ✅ End-to-end (Mozilla can't read) | ⚠️ Google can read |
| Source code | ✅ Open source | ❌ Proprietary |
| Telemetry control | ✅ Can fully disable | ⚠️ Limited |
| Fingerprinting resistance | ✅ resistFingerprinting | ⚠️ Limited |
The User Agent Situation
Firefox's default user agent identifies itself as Firefox. Some sites serve different or broken experiences to non-Chrome browsers.
If you encounter a broken site: check if disabling ETP for that site (shield icon → Turn off protection for this site) fixes it. If so, it was a tracker being blocked.
Avoid changing your user agent to Chrome — that creates a unique fingerprint (the only Firefox browser pretending to be Chrome on that IP).
LibreWolf: Hardened Firefox
If you want maximum privacy without manual configuration:
- LibreWolf ships Firefox with
resistFingerprinting = true, uBlock Origin installed, all telemetry disabled, and HTTPS-only mode on by default - No Pocket, no sponsored shortcuts
- Updated within days of Firefox releases
The trade-off: slightly more site breakage, slightly less fingerprint diversity (everyone using LibreWolf has the same fingerprint).
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