From 5d67d02bfa37caf1c5089734857633de1fb70c54 Mon Sep 17 00:00:00 2001
From: JorySeverijnse <jory@severijnse.eu>
Date: Wed, 4 Mar 2026 11:44:02 +0100
Subject: [PATCH] Initial arkenfox user.js commit

---
 README.md                              |  26 ++
 prefsCleaner.sh                        | 185 +++++++++++++
 scratchpad-scripts/arkenfox-cleanup.js | 168 ++++++++++++
 scratchpad-scripts/troubleshooter.js   | 210 +++++++++++++++
 user.js                                | 355 +++++++++++++++++++++++++
 5 files changed, 944 insertions(+)
 create mode 100644 README.md
 create mode 100755 prefsCleaner.sh
 create mode 100644 scratchpad-scripts/arkenfox-cleanup.js
 create mode 100644 scratchpad-scripts/troubleshooter.js
 create mode 100644 user.js

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..1a27d8a
--- /dev/null
+++ b/README.md
@@ -0,0 +1,26 @@
+### 🟪  user.js
+A `user.js` is a configuration file that can control Firefox settings - for a more technical breakdown and explanation, you can read more in the [wiki](https://github.com/arkenfox/user.js/wiki/2.1-User.js)
+
+### 🟩  the arkenfox user.js
+
+[![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
+
+The `arkenfox user.js` is a **template** which aims to provide as much privacy and enhanced security as possible, and to reduce tracking and fingerprinting as much as possible - while minimizing any loss of functionality and breakage (but it will happen).
+
+Everyone, experts included, should at least read the [wiki](https://github.com/arkenfox/user.js/wiki), as it contains important information regarding a few `user.js` settings. There is also an [interactive current release](https://arkenfox.github.io/gui/), thanks to [icpantsparti2](https://github.com/icpantsparti2).
+
+Note that we do *not* recommend connecting over Tor on Firefox. Use the [Tor Browser](https://www.torproject.org/projects/torbrowser.html.en) if your [threat model](https://2019.www.torproject.org/about/torusers.html) calls for it, or for accessing hidden services.
+
+Also be aware that the `arkenfox user.js` is made specifically for desktop Firefox. Using it as-is in other Gecko-based browsers can be counterproductive, especially in the Tor Browser.
+
+### 🟧  sitemap
+
+ - [releases](https://github.com/arkenfox/user.js/releases)
+ - [changelogs](https://github.com/arkenfox/user.js/issues?utf8=%E2%9C%93&q=is%3Aissue+label%3Achangelog)
+ - [wiki](https://github.com/arkenfox/user.js/wiki)
+ - [stickies](https://github.com/arkenfox/user.js/issues?q=is%3Aissue+is%3Aopen+label%3A%22sticky+topic%22)
+ - [diffs](https://github.com/arkenfox/user.js/issues?q=is%3Aissue+label%3Adiffs)
+ - [common questions and answers](https://github.com/arkenfox/user.js/issues?q=is%3Aissue+label%3Aanswered)
+
+### 🟥  acknowledgments
+Literally thousands of sources, references and suggestions. Many thanks, and much appreciated.
diff --git a/prefsCleaner.sh b/prefsCleaner.sh
new file mode 100755
index 0000000..b9739b2
--- /dev/null
+++ b/prefsCleaner.sh
@@ -0,0 +1,185 @@
+#!/usr/bin/env bash
+
+## prefs.js cleaner for Linux/Mac
+## author: @claustromaniac
+## version: 2.1
+
+## special thanks to @overdodactyl and @earthlng for a few snippets that I stol..*cough* borrowed from the updater.sh
+
+## DON'T GO HIGHER THAN VERSION x.9 !! ( because of ASCII comparison in update_prefsCleaner() )
+
+readonly CURRDIR=$(pwd)
+
+## get the full path of this script (readlink for Linux, greadlink for Mac with coreutils installed)
+SCRIPT_FILE=$(readlink -f "${BASH_SOURCE[0]}" 2>/dev/null || greadlink -f "${BASH_SOURCE[0]}" 2>/dev/null)
+
+## fallback for Macs without coreutils
+[ -z "$SCRIPT_FILE" ] && SCRIPT_FILE=${BASH_SOURCE[0]}
+
+
+AUTOUPDATE=true
+QUICKSTART=false
+
+## download method priority: curl -> wget
+DOWNLOAD_METHOD=''
+if command -v curl >/dev/null; then
+	DOWNLOAD_METHOD='curl --max-redirs 3 -so'
+elif command -v wget >/dev/null; then
+	DOWNLOAD_METHOD='wget --max-redirect 3 --quiet -O'
+else
+	AUTOUPDATE=false
+	echo -e "No curl or wget detected.\nAutomatic self-update disabled!"
+fi
+
+fQuit() {
+	## change directory back to the original working directory
+	cd "${CURRDIR}"
+	[ "$1" -eq 0 ] && echo -e "\n$2" || echo -e "\n$2" >&2
+	exit $1
+}
+
+fUsage() {
+	echo -e "\nUsage: $0 [-ds]"
+	echo -e "
+Optional Arguments:
+    -s           Start immediately
+    -d           Don't auto-update prefsCleaner.sh"
+}
+
+download_file() { # expects URL as argument ($1)
+  declare -r tf=$(mktemp)
+
+  $DOWNLOAD_METHOD "${tf}" "$1" &>/dev/null && echo "$tf" || echo '' # return the temp-filename or empty string on error
+}
+
+fFF_check() {
+	# there are many ways to see if firefox is running or not, some more reliable than others
+	# this isn't elegant and might not be future-proof but should at least be compatible with any environment
+	while [ -e lock ]; do
+		echo -e "\nThis Firefox profile seems to be in use. Close Firefox and try again.\n" >&2
+		read -r -p "Press any key to continue."
+	done
+}
+
+## returns the version number of a prefsCleaner.sh file
+get_prefsCleaner_version() {
+	echo "$(sed -n '5 s/.*[[:blank:]]\([[:digit:]]*\.[[:digit:]]*\)/\1/p' "$1")"
+}
+
+## updates the prefsCleaner.sh file based on the latest public version
+update_prefsCleaner() {
+	declare -r tmpfile="$(download_file 'https://raw.githubusercontent.com/arkenfox/user.js/master/prefsCleaner.sh')"
+	[ -z "$tmpfile" ] && echo -e "Error! Could not download prefsCleaner.sh" && return 1 # check if download failed
+
+	[[ $(get_prefsCleaner_version "$SCRIPT_FILE") == $(get_prefsCleaner_version "$tmpfile") ]] && return 0
+
+	mv "$tmpfile" "$SCRIPT_FILE"
+	chmod u+x "$SCRIPT_FILE"
+	"$SCRIPT_FILE" "$@" -d
+	exit 0
+}
+
+fClean() {
+	# the magic happens here
+	prefs="@@"
+	prefexp="user_pref[ 	]*\([ 	]*[\"']([^\"']+)[\"'][ 	]*,"
+	while read -r line; do
+		if [[ "$line" =~ $prefexp && $prefs != *"@@${BASH_REMATCH[1]}@@"* ]]; then
+			prefs="${prefs}${BASH_REMATCH[1]}@@"
+		fi
+	done <<< "$(grep -E "$prefexp" user.js)"
+
+	while IFS='' read -r line || [[ -n "$line" ]]; do
+		if [[ "$line" =~ ^$prefexp ]]; then
+			if [[ $prefs != *"@@${BASH_REMATCH[1]}@@"* ]]; then
+				echo "$line"
+			fi
+		else
+			echo "$line"
+		fi
+	done < "$1" > prefs.js
+}
+
+fStart() {
+	if [ ! -e user.js ]; then
+		fQuit 1 "user.js not found in the current directory."
+	elif [ ! -e prefs.js ]; then
+		fQuit 1 "prefs.js not found in the current directory."
+	fi
+
+	fFF_check
+	mkdir -p prefsjs_backups
+	bakfile="prefsjs_backups/prefs.js.backup.$(date +"%Y-%m-%d_%H%M")"
+	mv prefs.js "${bakfile}" || fQuit 1 "Operation aborted.\nReason: Could not create backup file $bakfile"
+	echo -e "\nprefs.js backed up: $bakfile"
+	echo "Cleaning prefs.js..."
+	fClean "$bakfile"
+	fQuit 0 "All done!"
+}
+
+
+while getopts "sd" opt; do
+	case $opt in
+		s)
+			QUICKSTART=true
+			;;
+		d)
+			AUTOUPDATE=false
+			;;
+	esac
+done
+
+## change directory to the Firefox profile directory
+cd "$(dirname "${SCRIPT_FILE}")"
+
+# Check if running as root and if any files have the owner as root/wheel.
+if [ "${EUID:-"$(id -u)"}" -eq 0 ]; then
+	fQuit 1 "You shouldn't run this with elevated privileges (such as with doas/sudo)."
+elif [ -n "$(find ./ -user 0)" ]; then
+	printf 'It looks like this script was previously run with elevated privileges,
+you will need to change ownership of the following files to your user:\n'
+	find . -user 0
+	fQuit 1
+fi
+
+[ "$AUTOUPDATE" = true ] && update_prefsCleaner "$@"
+
+echo -e "\n\n"
+echo "                   ╔══════════════════════════╗"
+echo "                   ║     prefs.js cleaner     ║"
+echo "                   ║    by claustromaniac     ║"
+echo "                   ║           v2.1           ║"
+echo "                   ╚══════════════════════════╝"
+echo -e "\nThis script should be run from your Firefox profile directory.\n"
+echo "It will remove any entries from prefs.js that also exist in user.js."
+echo "This will allow inactive preferences to be reset to their default values."
+echo -e "\nThis Firefox profile shouldn't be in use during the process.\n"
+
+[ "$QUICKSTART" = true ] && fStart
+
+echo -e "\nIn order to proceed, select a command below by entering its corresponding number.\n"
+
+select option in Start Help Exit; do
+	case $option in
+		Start)
+			fStart
+			;;
+		Help)
+			fUsage
+			echo -e "\nThis script creates a backup of your prefs.js file before doing anything."
+			echo -e "It should be safe, but you can follow these steps if something goes wrong:\n"
+			echo "1. Make sure Firefox is closed."
+			echo "2. Delete prefs.js in your profile folder."
+			echo "3. Delete Invalidprefs.js if you have one in the same folder."
+			echo "4. Rename or copy your latest backup to prefs.js."
+			echo "5. Run Firefox and see if you notice anything wrong with it."
+			echo "6. If you do notice something wrong, especially with your extensions, and/or with the UI, go to about:support, and restart Firefox with add-ons disabled. Then, restart it again normally, and see if the problems were solved."
+			echo -e "If you are able to identify the cause of your issues, please bring it up on the arkenfox user.js GitHub repository.\n"
+			;;
+		Exit)
+			fQuit 0
+			;;
+	esac
+done
+
+fQuit 0
diff --git a/scratchpad-scripts/arkenfox-cleanup.js b/scratchpad-scripts/arkenfox-cleanup.js
new file mode 100644
index 0000000..b1b44f5
--- /dev/null
+++ b/scratchpad-scripts/arkenfox-cleanup.js
@@ -0,0 +1,168 @@
+/***
+  This will reset the preferences that since FF91 have been
+  - removed from the arkenfox user.js
+  - deprecated by Mozilla but listed in the arkenfox user.js in the past
+
+  There is an archived version at https://github.com/arkenfox/user.js/issues/123
+  if you want the full list since jesus
+
+  Last updated: 14-August-2025
+
+  Instructions:
+  - [optional] close Firefox and backup your profile
+  - [optional] disable your network connection [1]
+  - start Firefox
+  - load about:config and press Ctrl+Shift+K to open the Web Console for about:config
+    - using about:config is important, so the script has the right permissions
+  - paste this script
+  - if you edited the list of prefs in the script, make sure the last pref does not have a trailing comma
+  - hit enter
+  - check the Info output to see which prefs were reset
+  - restart
+     - some prefs require a restart
+     - a restart will reapply your user.js
+  - [optional] re-enable your network connection
+ 
+  [1] Blocking Firefox from the internet ensures it cannot act on your reset preferences in the
+  period before you restart it, such as app and extension auto-updating, or downloading unwanted
+  components (GMP etc). It depends on what you're resetting and how long before you restart.
+
+***/
+
+(() => {
+
+  if ('undefined' === typeof(Services)) return alert('about:config needs to be the active tab!');
+
+  const aPREFS = [
+    /* DEPRECATED */
+    /* 129-140 */
+    'browser.shopping.experience2023.enabled', // 140
+    'browser.urlbar.pocket.featureGate', // 140
+    'media.ondevicechange.enabled', // 137
+    'webchannel.allowObject.urlWhitelist', // 132
+    /* 116-128 */
+    'browser.contentanalysis.default_allow', // 127
+    'browser.messaging-system.whatsNewPanel.enabled', // 126
+    'browser.ping-centre.telemetry', // 123
+    'dom.webnotifications.serviceworker.enabled', // 117
+    'javascript.use_us_english_locale', // 119
+    'layout.css.font-visibility.private', // 118
+    'layout.css.font-visibility.resistFingerprinting', // 116
+    'layout.css.font-visibility.standard', // 118
+    'layout.css.font-visibility.trackingprotection', // 118
+    'network.dns.skipTRR-when-parental-control-enabled', // 119
+    'permissions.delegation.enabled', // 118
+    'security.family_safety.mode', // 117
+    'widget.non-native-theme.enabled', // 127
+    /* 103-115 */
+    'browser.cache.offline.enable', // 115
+    'extensions.formautofill.heuristics.enabled', // 114
+    'network.cookie.lifetimePolicy', // 103 [technically removed in 104]
+    'privacy.clearsitedata.cache.enabled', // 114
+    'privacy.resistFingerprinting.testGranularityMask', // 114
+    'security.pki.sha1_enforcement_level', // 103
+    /* 92-102 */
+    'browser.urlbar.suggest.quicksuggest', // 95
+    'dom.securecontext.whitelist_onions', // 97
+    'dom.storage.next_gen', // 102
+    'network.http.spdy.enabled', // 100
+    'network.http.spdy.enabled.deps',
+    'network.http.spdy.enabled.http2',
+    'network.http.spdy.websockets',
+    'layout.css.font-visibility.level', // 94
+    'security.ask_for_password', // 102
+    'security.csp.enable', // 99
+    'security.password_lifetime', // 102
+    'security.ssl3.rsa_des_ede3_sha', // 93
+
+    /* REMOVED */
+    /* 129-140 */
+    'dom.securecontext.allowlist_onions',
+    'network.http.referer.hideOnionSource',
+    'privacy.clearOnShutdown.cache',
+    'privacy.clearOnShutdown.cookies',
+    'privacy.clearOnShutdown.downloads',
+    'privacy.clearOnShutdown.formdata',
+    'privacy.clearOnShutdown.history',
+    'privacy.clearOnShutdown.offlineApps',
+    'privacy.clearOnShutdown.sessions',
+    'privacy.cpd.cache',
+    'privacy.cpd.cookies',
+    'privacy.cpd.formdata',
+    'privacy.cpd.history',
+    'privacy.cpd.offlineApps',
+    'privacy.cpd.sessions',
+    /* 116-128 */
+    'browser.fixup.alternate.enabled',
+    'browser.taskbar.previews.enable',
+    'browser.urlbar.dnsResolveSingleWordsAfterSearch',
+    'geo.provider.network.url',
+    'geo.provider.network.logging.enabled',
+    'geo.provider.use_gpsd',
+    'media.gmp-widevinecdm.enabled',
+    'network.protocol-handler.external.ms-windows-store',
+    'privacy.partition.always_partition_third_party_non_cookie_storage',
+    'privacy.partition.always_partition_third_party_non_cookie_storage.exempt_sessionstorage',
+    'privacy.partition.serviceWorkers',
+    /* 103-115 */
+    'beacon.enabled',
+    'browser.startup.blankWindow',
+    'browser.newtab.preload',
+    'browser.newtabpage.activity-stream.feeds.discoverystreamfeed',
+    'browser.newtabpage.activity-stream.feeds.snippets',
+    'browser.region.network.url',
+    'browser.region.update.enabled',
+    'browser.search.region',
+    'browser.ssl_override_behavior',
+    'browser.tabs.warnOnClose',
+    'devtools.chrome.enabled',
+    'dom.disable_beforeunload',
+    'dom.disable_open_during_load',
+    'dom.netinfo.enabled',
+    'dom.vr.enabled',
+    'extensions.formautofill.addresses.supported',
+    'extensions.formautofill.available',
+    'extensions.formautofill.creditCards.available',
+    'extensions.formautofill.creditCards.supported',
+    'middlemouse.contentLoadURL',
+    'network.http.altsvc.oe',
+    /* 92-102 */
+    'browser.urlbar.trimURLs',
+    'dom.caches.enabled',
+    'dom.storageManager.enabled',
+    'dom.storage_access.enabled',
+    'dom.targetBlankNoOpener.enabled',
+    'network.cookie.thirdparty.sessionOnly',
+    'network.cookie.thirdparty.nonsecureSessionOnly',
+    'privacy.firstparty.isolate.block_post_message',
+    'privacy.firstparty.isolate.restrict_opener_access',
+    'privacy.firstparty.isolate.use_site',
+    'privacy.window.name.update.enabled',
+    'security.insecure_connection_text.enabled',
+
+    /* IMPORTANT: last active pref must not have a trailing comma */ 
+    /* reset parrot: check your open about:config after running the script */
+    '_user.js.parrot'
+  ];
+
+  console.clear();
+
+  let c = 0;
+  for (const sPname of aPREFS) {
+    if (Services.prefs.prefHasUserValue(sPname)) {
+      Services.prefs.clearUserPref(sPname);
+      if (!Services.prefs.prefHasUserValue(sPname)) {
+        console.info('reset', sPname);
+        c++;
+      } else console.warn('failed to reset', sPname);
+    }
+  }
+
+  focus();
+
+  const d = (c==1) ? ' pref' : ' prefs';
+  alert(c ? 'successfully reset ' + c + d + "\n\nfor details check the console" : 'nothing to reset');
+
+  return 'all done';
+
+})();
diff --git a/scratchpad-scripts/troubleshooter.js b/scratchpad-scripts/troubleshooter.js
new file mode 100644
index 0000000..bd86786
--- /dev/null
+++ b/scratchpad-scripts/troubleshooter.js
@@ -0,0 +1,210 @@
+/*** arkenfox user.js troubleshooter.js v1.6.3 ***/
+
+(function() {
+
+  if ("undefined" === typeof(Services)) return alert('about:config needs to be the active tab!');
+
+  const aPREFS = [
+
+    /* known culprits */
+    'network.cookie.cookieBehavior',
+    'network.http.referer.XOriginPolicy',
+    'privacy.firstparty.isolate',
+    'privacy.resistFingerprinting',
+    'security.mixed_content.block_display_content',
+    'svg.disabled',
+
+    /* Storage + Cache */
+    'browser.cache.offline.enable',
+    'dom.storage.enabled',
+    'dom.storageManager.enabled',
+
+    /* Workers, Web + Push Notifications */
+    'dom.caches.enabled',
+    'dom.push.connection.enabled',
+    'dom.push.enabled',
+    'dom.push.serverURL',
+    'dom.serviceWorkers.enabled',
+    'dom.webnotifications.enabled',
+    'dom.webnotifications.serviceworker.enabled',
+
+    /* Fonts */
+    'browser.display.use_document_fonts',
+    'font.blacklist.underline_offset',
+    'gfx.font_rendering.graphite.enabled',
+    'gfx.font_rendering.opentype_svg.enabled',
+    'layout.css.font-loading-api.enabled',
+
+    /* Misc */
+    'browser.link.open_newwindow.restriction',
+    'canvas.capturestream.enabled',
+    'dom.event.clipboardevents.enabled',
+    'dom.event.contextmenu.enabled',
+    'dom.IntersectionObserver.enabled',
+    'dom.popup_allowed_events',
+    'full-screen-api.enabled',
+    'intl.accept_languages',
+    'javascript.options.asmjs',
+    'javascript.options.wasm',
+    'permissions.default.shortcuts',
+
+    /* Hardware */
+    'dom.vr.enabled',
+    'media.ondevicechange.enabled',
+
+    /* Audio + Video */
+    'dom.webaudio.enabled',
+    'media.autoplay.default', // FF63+
+    'media.autoplay.blocking_policy', // FF78+
+
+    /* Forms */
+    'browser.formfill.enable',
+    'signon.autofillForms',
+    'signon.formlessCapture.enabled',
+
+    /* HTTPS */
+    'security.cert_pinning.enforcement_level',
+    'security.family_safety.mode',
+    'security.OCSP.require',
+    'security.pki.sha1_enforcement_level',
+    'security.ssl.require_safe_negotiation',
+    'security.ssl.treat_unsafe_negotiation_as_broken',
+    'security.ssl3.dhe_rsa_aes_128_sha',
+    'security.ssl3.dhe_rsa_aes_256_sha',
+    'security.ssl3.ecdhe_ecdsa_aes_128_sha',
+    'security.ssl3.ecdhe_rsa_aes_128_sha',
+    'security.ssl3.rsa_aes_128_sha',
+    'security.ssl3.rsa_aes_256_sha',
+    'security.ssl3.rsa_des_ede3_sha',
+    'security.tls.enable_0rtt_data',
+    'security.tls.version.max',
+    'security.tls.version.min',
+
+    /* Plugins + Flash */
+    'plugin.default.state',
+    'plugin.state.flash',
+
+    /* unlikely to cause problems */
+    'dom.popup_maximum',
+    'geo.provider.network.url',
+    'layout.css.visited_links_enabled',
+    'mathml.disabled',
+    'network.auth.subresource-http-auth-allow',
+    'network.http.redirection-limit',
+    'network.protocol-handler.external.ms-windows-store',
+    'privacy.trackingprotection.enabled',
+    'security.data_uri.block_toplevel_data_uri_navigations',
+    'privacy.window.name.update.enabled', // FF82+
+
+    'last.one.without.comma'
+  ]
+
+  // any runtime-set pref that everyone will have and that can be safely reset
+  const oFILLER = { type: 64, name: 'app.update.lastUpdateTime.browser-cleanup-thumbnails', value: 1580000000 };
+
+  function getMyList(arr) {
+    const aRet = [];
+    for (const sPname of arr) {
+      if (Services.prefs.prefHasUserValue(sPname)) {
+        const ptype = Services.prefs.getPrefType(sPname);
+        switch (ptype) {
+          case 32: // string (see https://dxr.mozilla.org/mozilla-central/source/modules/libpref/nsIPrefBranch.idl#31)
+            aRet.push({'type':ptype,'name':sPname,'value':Services.prefs.getCharPref(sPname)});
+            break;
+          case 64: // int
+            aRet.push({'type':ptype,'name':sPname,'value':Services.prefs.getIntPref(sPname)});
+            break;
+          case 128: // boolean
+            aRet.push({'type':ptype,'name':sPname,'value':Services.prefs.getBoolPref(sPname)});
+            break;
+          default:
+            console.log("error detecting pref-type for '"+sPname+"' !");
+        }
+      }
+    }
+    return aRet;
+  }
+
+  function reapply(arr) {
+    for (const oPref of arr) {
+      switch (oPref.type) {
+        case 32: // string
+          Services.prefs.setCharPref(oPref.name, oPref.value);
+          break;
+        case 64: // int
+          Services.prefs.setIntPref(oPref.name, oPref.value);
+          break;
+        case 128: // boolean
+          Services.prefs.setBoolPref(oPref.name, oPref.value);
+          break;
+        default:
+          console.log("error re-appyling value for '"+oPref.name+"' !"); // should never happen
+      }
+    }
+  }
+
+  function myreset(arr) {
+    for (const oPref of arr) Services.prefs.clearUserPref(oPref.name);
+  }
+
+  function resetAllMatchingDefault(arr) {
+    const aTmp = getMyList(arr);
+    myreset(aTmp);
+    reapply(aTmp);
+  }
+
+  function _main(aALL) {
+    const _h = (arr) => Math.ceil(arr.length/2);
+
+    let aTmp = aALL, aDbg = aALL;
+    reapply(aALL);
+    myreset(aTmp.slice(0, _h(aTmp)));
+    while (aTmp.length) {
+      alert('NOW TEST AGAIN !');
+      if (confirm('if the problem still exists click OK, otherwise click Cancel.')) {
+        aTmp = aTmp.slice(_h(aTmp));
+      } else {
+        aTmp = aTmp.slice(0, _h(aTmp));
+        aDbg = aTmp; // update narrowed down list
+        if (aDbg.length == 1) break;
+      }
+      reapply(aALL);
+      myreset(aTmp.slice(0, _h(aTmp))); // reset half of the remaining prefs
+    }
+    reapply(aALL);
+
+    if (aDbg.length == 1) return alert("narrowed it down to:\n\n"+aDbg[0].name+"\n");
+    if (aDbg.length == aALL.length) {
+      const msg = "Failed to narrow it down beyond the initial "+aALL.length+" prefs. The problem is most likely caused by at least 2 prefs!\n\n" +
+            "Either those prefs are too far apart in the list or there are exactly 2 culprits and they just happen to be at the wrong place.\n\n" +
+            "In case it's the latter, the script can add a dummy pref and you can try again - Try again?";
+      if (confirm(msg)) return _main([...aALL, oFILLER]);
+    } else if (aDbg.length > 10 && confirm("Narrowed it down to "+aDbg.length+" prefs. Try narrowing it down further?")) {
+      return _main(aDbg.reverse());
+    }
+
+    alert("Narrowed it down to "+ aDbg.length.toString() +" prefs, check the console ...");
+    console.log('The problem is caused by 2 or more of these prefs:');
+    for (const oPref of aDbg) console.log(oPref.name);
+  }
+
+
+  resetAllMatchingDefault(aPREFS); // reset user-set prefs matching FFs default value
+
+  const aBAK = getMyList(aPREFS);
+  //console.log(aBAK.length, "user-set prefs from our list detected and their values stored.");
+
+  const sMsg = "all detected prefs reset.\n\n" +
+        "!! KEEP THIS PROMPT OPEN AND TEST THE SITE IN ANOTHER TAB !!\n\n" +
+        "IF the problem still exists, this script can't help you - click Cancel to re-apply your values and exit.\n\n" +
+        "Click OK if your problem is fixed.";
+
+  focus();
+  myreset(aBAK);
+  if (!confirm(sMsg)) {
+    reapply(aBAK);
+    return;
+  }
+  _main(aBAK);
+
+})();
diff --git a/user.js b/user.js
new file mode 100644
index 0000000..2fdb59e
--- /dev/null
+++ b/user.js
@@ -0,0 +1,355 @@
+user_pref("_user.js.parrot", "START: Oh yes, the Norwegian Blue... what's wrong with it?");
+
+user_pref("browser.aboutConfig.showWarning", false);
+
+user_pref("_user.js.parrot", "0100 syntax error: the parrot's dead!");
+
+user_pref("browser.startup.page", 0);
+
+user_pref("browser.startup.homepage", "chrome://browser/content/blanktab.html");
+
+user_pref("browser.newtabpage.enabled", false);
+
+user_pref("browser.newtabpage.activity-stream.showSponsored", false);
+
+user_pref("browser.newtabpage.activity-stream.showSponsoredTopSites", false);
+
+user_pref("browser.newtabpage.activity-stream.showSponsoredCheckboxes", false);
+
+user_pref("browser.newtabpage.activity-stream.default.sites", "");
+
+user_pref("_user.js.parrot", "0200 syntax error: the parrot's definitely deceased!");
+
+user_pref("geo.provider.ms-windows-location", false);
+
+user_pref("geo.provider.use_corelocation", false);
+
+user_pref("geo.provider.use_geoclue", false);
+
+user_pref("_user.js.parrot", "0300 syntax error: the parrot's not pinin' for the fjords!");
+
+user_pref("extensions.getAddons.showPane", false);
+
+user_pref("extensions.htmlaboutaddons.recommendations.enabled", false);
+
+user_pref("browser.discovery.enabled", false);
+
+user_pref("browser.newtabpage.activity-stream.feeds.telemetry", false);
+
+user_pref("browser.newtabpage.activity-stream.telemetry", false);
+
+user_pref("app.shield.optoutstudies.enabled", false);
+
+user_pref("app.normandy.enabled", false);
+
+user_pref("app.normandy.api_url", "");
+
+user_pref("breakpad.reportURL", "");
+
+user_pref("browser.tabs.crashReporting.sendReport", false);
+
+user_pref("browser.crashReports.unsubmittedCheck.autoSubmit2", false);
+
+user_pref("captivedetect.canonicalURL", "");
+
+user_pref("network.captive-portal-service.enabled", false);
+
+user_pref("network.connectivity-service.enabled", false);
+
+user_pref("_user.js.parrot", "0400 syntax error: the parrot's passed on!");
+
+user_pref("browser.safebrowsing.downloads.remote.enabled", false);
+
+user_pref("_user.js.parrot", "0600 syntax error: the parrot's no more!");
+
+user_pref("network.prefetch-next", false);
+
+user_pref("network.dns.disablePrefetch", true);
+
+user_pref("network.dns.disablePrefetchFromHTTPS", true);
+
+user_pref("network.predictor.enabled", false);
+
+user_pref("network.predictor.enable-prefetch", false);
+
+user_pref("network.http.speculative-parallel-limit", 0);
+
+user_pref("browser.places.speculativeConnect.enabled", false);
+
+user_pref("_user.js.parrot", "0700 syntax error: the parrot's given up the ghost!");
+
+user_pref("network.proxy.socks_remote_dns", true);
+
+user_pref("network.file.disable_unc_paths", true);
+
+user_pref("network.gio.supported-protocols", "");
+
+user_pref("_user.js.parrot", "0800 syntax error: the parrot's ceased to be!");
+
+user_pref("browser.urlbar.speculativeConnect.enabled", false);
+
+user_pref("browser.urlbar.quicksuggest.enabled", false);
+
+user_pref("browser.urlbar.suggest.quicksuggest.nonsponsored", false);
+
+user_pref("browser.urlbar.suggest.quicksuggest.sponsored", false);
+
+user_pref("browser.search.suggest.enabled", false);
+
+user_pref("browser.urlbar.suggest.searches", false);
+
+user_pref("browser.urlbar.trending.featureGate", false);
+
+user_pref("browser.urlbar.addons.featureGate", false);
+
+user_pref("browser.urlbar.amp.featureGate", false);
+
+user_pref("browser.urlbar.fakespot.featureGate", false);
+
+user_pref("browser.urlbar.mdn.featureGate", false);
+
+user_pref("browser.urlbar.weather.featureGate", false);
+
+user_pref("browser.urlbar.wikipedia.featureGate", false);
+
+user_pref("browser.urlbar.yelp.featureGate", false);
+
+user_pref("browser.formfill.enable", false);
+
+user_pref("browser.search.separatePrivateDefault", true);
+
+user_pref("browser.search.separatePrivateDefault.ui.enabled", true);
+
+user_pref("_user.js.parrot", "0900 syntax error: the parrot's expired!");
+
+user_pref("signon.autofillForms", false);
+
+user_pref("signon.formlessCapture.enabled", false);
+
+user_pref("network.auth.subresource-http-auth-allow", 1);
+
+user_pref("_user.js.parrot", "1000 syntax error: the parrot's gone to meet 'is maker!");
+
+user_pref("browser.cache.disk.enable", false);
+
+user_pref("browser.privatebrowsing.forceMediaMemoryCache", true);
+
+user_pref("media.memory_cache_max_size", 65536);
+
+user_pref("browser.sessionstore.privacy_level", 2);
+
+user_pref("toolkit.winRegisterApplicationRestart", false);
+
+user_pref("browser.shell.shortcutFavicons", false);
+
+user_pref("_user.js.parrot", "1200 syntax error: the parrot's a stiff!");
+
+user_pref("security.ssl.require_safe_negotiation", true);
+
+user_pref("security.tls.enable_0rtt_data", false);
+
+user_pref("security.OCSP.enabled", 1);
+
+user_pref("security.OCSP.require", true);
+
+user_pref("security.cert_pinning.enforcement_level", 2);
+
+user_pref("security.remote_settings.crlite_filters.enabled", true);
+
+user_pref("security.pki.crlite_mode", 2);
+
+user_pref("dom.security.https_only_mode", true);
+
+user_pref("dom.security.https_only_mode_send_http_background_request", false);
+
+user_pref("security.ssl.treat_unsafe_negotiation_as_broken", true);
+
+user_pref("browser.xul.error_pages.expert_bad_cert", true);
+
+user_pref("_user.js.parrot", "1600 syntax error: the parrot rests in peace!");
+
+user_pref("network.http.referer.XOriginTrimmingPolicy", 2);
+
+user_pref("_user.js.parrot", "1700 syntax error: the parrot's bit the dust!");
+
+user_pref("privacy.userContext.enabled", true);
+
+user_pref("privacy.userContext.ui.enabled", true);
+
+user_pref("_user.js.parrot", "2000 syntax error: the parrot's snuffed it!");
+
+user_pref("media.peerconnection.ice.proxy_only_if_behind_proxy", true);
+
+user_pref("media.peerconnection.ice.default_address_only", true);
+
+user_pref("_user.js.parrot", "2400 syntax error: the parrot's kicked the bucket!");
+
+user_pref("dom.disable_window_move_resize", true);
+
+user_pref("_user.js.parrot", "2600 syntax error: the parrot's run down the curtain!");
+
+user_pref("browser.download.start_downloads_in_tmp_dir", true);
+
+user_pref("browser.helperApps.deleteTempFileOnExit", true);
+
+user_pref("browser.uitour.enabled", false);
+
+user_pref("devtools.debugger.remote-enabled", false);
+
+user_pref("permissions.manager.defaultsUrl", "");
+
+user_pref("network.IDN_show_punycode", true);
+
+user_pref("pdfjs.disabled", false);
+
+user_pref("pdfjs.enableScripting", false);
+
+user_pref("browser.tabs.searchclipboardfor.middleclick", false);
+
+user_pref("browser.contentanalysis.enabled", false);
+
+user_pref("browser.contentanalysis.default_result", 0);
+
+user_pref("security.csp.reporting.enabled", false);
+
+user_pref("browser.download.useDownloadDir", false);
+
+user_pref("browser.download.alwaysOpenPanel", false);
+
+user_pref("browser.download.manager.addToRecentDocs", false);
+
+user_pref("browser.download.always_ask_before_handling_new_types", true);
+
+user_pref("extensions.enabledScopes", 5);
+
+user_pref("extensions.postDownloadThirdPartyPrompt", false);
+
+user_pref("_user.js.parrot", "2700 syntax error: the parrot's joined the bleedin' choir invisible!");
+
+user_pref("browser.contentblocking.category", "strict");
+
+user_pref("_user.js.parrot", "2800 syntax error: the parrot's bleedin' demised!");
+
+user_pref("privacy.sanitize.sanitizeOnShutdown", true);
+
+user_pref("privacy.clearOnShutdown_v2.cache", true);
+
+user_pref("privacy.clearOnShutdown_v2.historyFormDataAndDownloads", false);
+
+user_pref("privacy.clearOnShutdown_v2.browsingHistoryAndDownloads", false);
+
+user_pref("privacy.clearOnShutdown_v2.downloads", false);
+
+user_pref("privacy.clearOnShutdown_v2.formdata", true);
+
+user_pref("privacy.clearOnShutdown_v2.cookiesAndStorage", true);
+
+user_pref("privacy.clearSiteData.cache", true);
+
+user_pref("privacy.clearSiteData.cookiesAndStorage", false);
+
+user_pref("privacy.clearSiteData.historyFormDataAndDownloads", false);
+
+user_pref("privacy.clearSiteData.browsingHistoryAndDownloads", false);
+
+user_pref("privacy.clearSiteData.formdata", true);
+
+user_pref("privacy.clearHistory.cache", true);
+
+user_pref("privacy.clearHistory.cookiesAndStorage", false);
+
+user_pref("privacy.clearHistory.historyFormDataAndDownloads", false);
+
+user_pref("privacy.clearHistory.browsingHistoryAndDownloads", false);
+
+user_pref("privacy.clearHistory.formdata", true);
+
+user_pref("privacy.sanitize.timeSpan", 0);
+
+user_pref("_user.js.parrot", "4000 syntax error: the parrot's bereft of life!");
+
+user_pref("_user.js.parrot", "4500 syntax error: the parrot's popped 'is clogs");
+
+user_pref("privacy.window.maxInnerWidth", 1600);
+
+user_pref("privacy.window.maxInnerHeight", 900);
+
+user_pref("privacy.resistFingerprinting.block_mozAddonManager", true);
+
+user_pref("privacy.spoof_english", 1);
+
+user_pref("widget.non-native-theme.use-theme-accent", false);
+
+user_pref("browser.link.open_newwindow", 3);
+
+user_pref("browser.link.open_newwindow.restriction", 0);
+
+user_pref("_user.js.parrot", "5000 syntax error: the parrot's taken 'is last bow");
+
+user_pref("_user.js.parrot", "5500 syntax error: this is an ex-parrot!");
+
+user_pref("_user.js.parrot", "6000 syntax error: the parrot's 'istory!");
+
+user_pref("extensions.blocklist.enabled", true);
+
+user_pref("network.http.referer.spoofSource", false);
+
+user_pref("security.dialog_enable_delay", 1e3);
+
+user_pref("privacy.firstparty.isolate", false);
+
+user_pref("extensions.webcompat.enable_shims", true);
+
+user_pref("security.tls.version.enable-deprecated", false);
+
+user_pref("extensions.webcompat-reporter.enabled", false);
+
+user_pref("extensions.quarantinedDomains.enabled", true);
+
+user_pref("_user.js.parrot", "7000 syntax error: the parrot's pushing up daisies!");
+
+user_pref("_user.js.parrot", "8000 syntax error: the parrot's crossed the Jordan");
+
+user_pref("_user.js.parrot", "8500 syntax error: the parrot's off the twig!");
+
+user_pref("datareporting.policy.dataSubmissionEnabled", false);
+
+user_pref("datareporting.healthreport.uploadEnabled", false);
+
+user_pref("toolkit.telemetry.unified", false);
+
+user_pref("toolkit.telemetry.enabled", false);
+
+user_pref("toolkit.telemetry.server", "data:,");
+
+user_pref("toolkit.telemetry.archive.enabled", false);
+
+user_pref("toolkit.telemetry.newProfilePing.enabled", false);
+
+user_pref("toolkit.telemetry.shutdownPingSender.enabled", false);
+
+user_pref("toolkit.telemetry.updatePing.enabled", false);
+
+user_pref("toolkit.telemetry.bhrPing.enabled", false);
+
+user_pref("toolkit.telemetry.firstShutdownPing.enabled", false);
+
+user_pref("toolkit.telemetry.coverage.opt-out", true);
+
+user_pref("toolkit.coverage.opt-out", true);
+
+user_pref("toolkit.coverage.endpoint.base", "");
+
+user_pref("_user.js.parrot", "9000 syntax error: the parrot's cashed in 'is chips!");
+
+user_pref("browser.startup.homepage_override.mstone", "ignore");
+
+user_pref("browser.newtabpage.activity-stream.asrouter.userprefs.cfr.addons", false);
+
+user_pref("browser.newtabpage.activity-stream.asrouter.userprefs.cfr.features", false);
+
+user_pref("browser.urlbar.showSearchTerms.enabled", false);
+
+user_pref("_user.js.parrot", "9999 syntax error: the parrot's shuffled off 'is mortal coil!");
+
+user_pref("_user.js.parrot", "SUCCESS: No no he's not dead, he's, he's restin'!");
\ No newline at end of file