Firefox config - Privacy focused, no telemetry, no AI

user.js

/****************************************************************************
 *  HARDENED FIREFOX USER.JS — PRIVACY FIRST, NO AI, NO TELEMETRY
 ****************************************************************************/

/******************************************************************************
 * SECTION 1: MOZILLA AI / FIREFOX SUGGEST
 ******************************************************************************/

/*** AI Chat sidebar / GenAI integration ***/
user_pref('browser.ml.chat.enabled', false);

/*** Firefox Suggest (sponsored + non-sponsored URL bar suggestions) ***/
user_pref('browser.urlbar.quicksuggest.enabled', false);
user_pref('browser.urlbar.quicksuggest.dataCollection.enabled', false);
user_pref('browser.urlbar.suggest.quicksuggest.sponsored', false);
user_pref('browser.urlbar.suggest.quicksuggest.nonsponsored', false);

/******************************************************************************
 * SECTION 2: TELEMETRY, EXPERIMENTS, DATA COLLECTION
 ******************************************************************************/

user_pref('toolkit.telemetry.enabled', false);
user_pref('toolkit.telemetry.unified', false);
user_pref('toolkit.telemetry.server', '');
user_pref('toolkit.telemetry.archive.enabled', false);
user_pref('toolkit.coverage.enabled', false);
user_pref('toolkit.coverage.opt-out', true);
user_pref('datareporting.healthreport.uploadEnabled', false);

user_pref('app.shield.optoutstudies.enabled', false); // Shield experiments
user_pref('app.normandy.enabled', false); // Normandy
user_pref('app.normandy.api_url', '');

/******************************************************************************
 * SECTION 3: NETWORK / IDENTIFIERS / FINGERPRINTING RESISTANCE
 ******************************************************************************/

/*** Tracking protection (strict mode) ***/
user_pref('privacy.trackingprotection.enabled', true);
user_pref('privacy.trackingprotection.pbmode.enabled', true);
user_pref('privacy.trackingprotection.emailtracking.enabled', true);
user_pref('privacy.trackingprotection.cryptomining.enabled', true);
user_pref('privacy.trackingprotection.fingerprinting.enabled', true);

/*** Fingerprinting resistance (covers all modes) ***/
user_pref('privacy.resistFingerprinting', true);

/*** Query stripping (URL tracking parameters) ***/
user_pref('privacy.query_stripping.enabled', true);
user_pref('privacy.query_stripping.strip_on_share', true);

/*** WebGL (major fingerprinting vector) ***/
user_pref('webgl.disabled', true);

/*** Speculative connections ***/
user_pref('network.predictor.enabled', false);
user_pref('network.dns.disablePrefetch', true);
user_pref('network.prefetch-next', false);
user_pref('network.http.speculative-parallel-limit', 0);

/******************************************************************************
 * SECTION 4: COOKIES, STORAGE, AND ISOLATION
 ******************************************************************************/

/*** Total cookie protection (partitioned cookies) ***/
user_pref('network.cookie.cookieBehavior', 5);

/*** Storage partitioning ***/
user_pref('privacy.partition.network_state', true);
user_pref('privacy.partition.serviceWorkers', true);

/******************************************************************************
 * SECTION 5: SEARCH, SUGGESTIONS, NEW TAB PAGE
 ******************************************************************************/

/*** Search suggestions in the URL bar ***/
user_pref('browser.search.suggest.enabled', false);
user_pref('browser.urlbar.suggest.searches', false);

/*** sponsored content ***/
user_pref('browser.newtabpage.activity-stream.showSponsoredTopSites', false);

/*** Pocket recommendation system ***/
user_pref('extensions.pocket.enabled', false);
user_pref('browser.newtabpage.activity-stream.feeds.section.topstories', false);

/******************************************************************************
 * SECTION 6: PERMISSIONS AND FEATURES THAT LEAK DATA
 ******************************************************************************/

/*** WebRTC (can leak local IPs) ***/
user_pref('media.peerconnection.enabled', false);

/*** Geolocation ***/
user_pref('geo.enabled', false);

/*** DRM ***/
user_pref('media.eme.enabled', false);

/*** Autoplay (block all) ***/
user_pref('media.autoplay.default', 5);

/******************************************************************************
 * SECTION 7: HTTPS AND CONNECTION SECURITY
 ******************************************************************************/

/*** HTTPS-only mode (HTTP downgrades blocked) ***/
user_pref('dom.security.https_only_mode', true);
user_pref('dom.security.https_only_mode_pbm', true);

/*** Block passive mixed content (HTTP images/video on HTTPS pages) ***/
user_pref('security.mixed_content.block_display_content', true);

/*** Captive portal detection (leaks to captive-detect.mozilla.com) ***/
user_pref('network.captive-portal-service.enabled', false);
user_pref('captivedetect.canonicalURL', '');
user_pref('network.connectivity-service.enabled', false);

/*** Referrer policy: strip to origin, send only to same-origin ***/
user_pref('network.http.referer.XOriginPolicy', 2);
user_pref('network.http.referer.XOriginTrimmingPolicy', 2);

/*** Web push notifications ***/
user_pref('dom.push.enabled', false);
user_pref('dom.webnotifications.enabled', false);

/******************************************************************************
 * SECTION 8: UI TWEAKS
 ******************************************************************************/

/*** Default-browser check and spotlight/messaging promotions ***/
user_pref('browser.shell.checkDefaultBrowser', false);
user_pref('browser.startup.upgradeDialog.enabled', false);
user_pref('browser.newtabpage.activity-stream.asrouter.userprefs.cfr.features', false);
user_pref('browser.newtabpage.activity-stream.asrouter.userprefs.cfr.addons', false);

/*** Add-on recommendations (phones home to addons.mozilla.org) ***/
user_pref('extensions.getAddons.showPane', false);
user_pref('extensions.htmlaboutaddons.recommendations.enabled', false);

/*** Form history autofill ***/
user_pref('browser.formfill.enable', false);

/*** Set toolbar density to "Compact (not supported)" ***/
user_pref('browser.uidensity', 1);