A comprehensive list of Firefox privacy and security settings
By cuter

A comprehensive list of Firefox privacy and security settings

25/05/2022  |   147 Views

Mozilla Firefox is without doubt the web browser that gives the most control to users in regards to privacy and security. Firefox users find some of those options listed in the graphical user interface, but full control over the browser is only granted if changes are made to the browser's configuration.

This can be done on the about:config page, or by placing a user.js file in the profile directory of the Firefox user.

The following list is a work in progress. Firefox is updated regularly and preferences may change because of this. There may be new features and new preferences as well, and the idea of this guide is to get a discussion going that improves this list on a continuous basis.

I'd like to thank Ghacks' reader Pants for creating the list and giving me permission to publish it here on the site.

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Note: If you prefer to use about:config to manipulate those entries, check out our overview of Firefox privacy and security about:config settings which lists all preferences and values you can set them to.

How to get started

If you have used the list in the past, start with the changelog to find out what is new and changed.

If this is your first time, read the introduction below first, backup your user.js file as instructed below, and go through the listing one by one to modify it according to your needs.

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It is highly suggested to go through the list before you place it in the Firefox profile folder as you may disable features that you require in the process.

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You may edit the list in any plain text editor, and use comment syntax // at the beginning of each line to block a preference from being set.

Make sure you save it as a user.js file in the end.

  1. Type about:support in the Firefox address bar.
  2. Click the show folder link under application basics to open the profile folder on the computer system.
  3. Backup the prefs.js file.
  4. Copy the user.js file into the root of the profile folder.
  5. Restart Firefox.

Why backup prefs.js prior to this? Because any user.js preference that is legitimate is written to prefs.js when you place the user.js file in the profile folder. This means that the changes remain even if you delete it afterwards.

The privacy and security list

You can download the most recent version of the list with a click on the following link: user.js-ghacks-0.11.zip

Alternatively, you may load a custom HTML version of the list: User.js Light or User.js Dark, and load the changelog directly as well.

Please Note: Always use the latest download, as the many changes may get out of sync with what's on display in the article. Expect future versions to be less frequent, as the magnificent Pants (who is this guy? is he a wizard?) has decided to take charge of all changes, and will let the comments build up for at least a few days at a time.

Make sure you check the changelog that is included in the download as it lists changes made in recent versions.

/******* name: ghacks user.js* date: 11 Feb 2017* version: 0.11 FINAL : The [White?] House of the Rising Pants*Â Â"My mother was a tailor, she sewed my new blue pants"* FF version: 51 (DESKTOP)* authors:ÂFLOTUS: PantsVICE PRESIDENT: earthling (birth certificate on request)SECRETARY: Martin BrinkmannSPEAKER: Tom HawackCABINET: Just me, Conker, Rockin' Jerry, Ainatar, Parker Lewis* url: * required reading: http://kb.mozillazine.org/User.js_file

README/IMPORTANT:

End users of this list/file are expected to know what they are doing. These are the author's settings.

The author does NOT expect (or indeed want) end users to just run with it as is.Use it as a comprehensive list, or as a template for your own.

Extensive links and comments have been added to help. Before using this user.js, if necessary, you should change, remove or comment out with two forward slashes any preferences you're not happy with or not sure about.

The settings in this file (user.js) OVERWRITE the ones in your prefs (prefs.js - these are accessed via about:config) when FF is started. See the required reading above.

BACKUP FIRST:

Backup your profile first, or even just the PREFS.JS. Go to your profile directory and copyÂprefs.js, rename it (eg to prefs.js.backup). That way, if you have problems, to restore FF Âto the state it was in beforehand, close FF, delete the prefs.js, rename your backup copy ofÂprefs back to prefs.js, RENAME the user.js so it doesn't overwrite everything again, thenÂstart FF. IF you have any problems, you can also ask in the comments at ghacks.

PURPOSE:

This is not a "comprehensive" list of ALL things privacy/security (otherwise it would be huge)ÂIt is more like a list of settings that generally differ from their defaults, and is aimed atÂimproving security and privacy, at making a "quieter" FF, and at reducing fingerprinting andÂtracking; while allowing functionality. There will be trade-offs and conflicts between these.

COMMON ISSUES:

Some prefs will break some sites (it's inevitable). If you are having issues search forÂ"WARNING:" in this document, especially the ones listed just below.

This user.js uses the author's settings, so you need to check these EACH release becausethe author prefers anonymity, security, and privacy over functionality [eg being able topaste in Facebook, downloadable fonts, and other minor inconveniences]. You have been warned.

THANKS:

Special thanks to Martin Brinkmann and the ghacks communityLots of websites, lots of people, too many to list but here are some excellent resources

******/

// START: internal custom pref to test for syntax errors (thanks earthling)// Yes, this next pref setting is redundant, but I like it!// https://en.wikipedia.org/wiki/Dead_parrot// https://en.wikipedia.org/wiki/Warrant_canaryuser_pref("ghacks_user.js.parrot", "Oh yes, the Norwegian Blue... what's wrong with it?");

0100: STARTUP

user_pref("ghacks_user.js.parrot", "0100 syntax error: the parrot's dead!");

// 0101: disable "slow startup" options// warnings, disk history, welcomes, intros, EULA, default browser checkuser_pref("browser.slowStartup.notificationDisabled", true);user_pref("browser.slowStartup.maxSamples", 0);user_pref("browser.slowStartup.samples", 0);user_pref("browser.rights.3.shown", true);user_pref("browser.startup.homepage_override.mstone", "ignore");user_pref("startup.homepage_welcome_url", "");user_pref("startup.homepage_welcome_url.additional", "");user_pref("startup.homepage_override_url", "");user_pref("browser.laterrun.enabled", false);user_pref("browser.shell.checkDefaultBrowser", false);user_pref("browser.usedOnWindows10.introURL", "");

// 0102: set start page (0=blank, 1=home, 2=last visited page, 3=resume previous session)// home = browser.startup.homepage preference// You can set all of this from Options>General>Startup// user_pref("browser.startup.page", 0);

0200: GEOLOCATION

user_pref("ghacks_user.js.parrot", "0200 syntax error: the parrot's definitely deceased!");

// 0201: disable location-aware browsinguser_pref("geo.enabled", false);user_pref("geo.wifi.uri", "https://127.0.0.1");user_pref("geo.wifi.logging.enabled", false); // (hidden pref)user_pref("browser.search.geoip.url", "");user_pref("geo.wifi.xhr.timeout", 1);user_pref("browser.search.geoip.timeout", 1);

// 0202: disable GeoIP-based search results// NOTE: may not be hidden if Mozilla have changed your settings due to your locale// https://trac.torproject.org/projects/tor/ticket/16254user_pref("browser.search.countryCode", "US"); // (hidden pref)user_pref("browser.search.region", "US"); // (hidden pref)

// 0203: disable using OS locale, force APP localeuser_pref("intl.locale.matchOS", false);

// 0204: set APP localuser_pref("general.useragent.locale", "en-US");

// 0206: disable geographically specific results/search engines eg: "browser.search.*.US"// i.e ignore all of Mozilla's multiple deals with multiple engines in multiple localesuser_pref("browser.search.geoSpecificDefaults", false);user_pref("browser.search.geoSpecificDefaults.url", "");

// 0207: set language to match// WARNING: reset this to your default if you don't want Englishuser_pref("intl.accept_languages", "en-US, en");

// 0208: enforce US English locale regardless of the system locale// https://bugzilla.mozilla.org/show_bug.cgi?id=867501user_pref("javascript.use_us_english_locale", true); // (hidden pref)

0300: QUIET FOX [PART 1]

user_pref("ghacks_user.js.parrot", "0300 syntax error: the parrot's not pinin' for the fjords!");

// 0301: disable browser auto update// Options>Advanced>Update>Never check for updates

user_pref("app.update.enabled", false);// Options>Advanced>Update>Use a background service to install updatesuser_pref("app.update.service.enabled", false);// ensure update information is not suppresseduser_pref("app.update.silent", false);// disable background update staginguser_pref("app.update.staging.enabled", false);

// 0302: disable browser auto installing update when you do a manual checkuser_pref("app.update.auto", false);

// 0303: disable search update (Options>Advanced>Update>Automatically update: search engines)user_pref("browser.search.update", false);

// 0304: disable add-ons auto checking for new versionsuser_pref("extensions.update.enabled", false);

// 0305: disable add-ons auto updateuser_pref("extensions.update.autoUpdateDefault", false);

// 0306: disable add-on metadata updating// sends daily pings to Mozilla about extensions and recent startupsuser_pref("extensions.getAddons.cache.enabled", false);

// 0307: disable auto updating of personas (themes)user_pref("lightweightThemes.update.enabled", false);

// 0309: disable sending Flash crash reportsuser_pref("dom.ipc.plugins.flash.subprocess.crashreporter.enabled", false);

// 0310: disable sending the URL of the website where a plugin crasheduser_pref("dom.ipc.plugins.reportCrashURL", false);

// 0320: disable extension discovery// featured extensions for displaying in Get Add-ons paneluser_pref("extensions.webservice.discoverURL", "http://127.0.0.1");

// 0330a: disable telemetry// https://gecko.readthedocs.org/en/latest/toolkit/components/telemetry/telemetry/preferences.html// the pref (.unified) affects the behaviour of the pref (.enabled)// IF unified=false then .enabled controls the telemetry module// IF unified=true then .enabled ONLY controls whether to record extended data// so make sure to have both set as falseuser_pref("toolkit.telemetry.unified", false);user_pref("toolkit.telemetry.enabled", false);

// 0330b: set unifiedIsOptIn to make sure telemetry respects OptIn choice and that telemetry// is enabled ONLY for people that opted into it, even if unified Telemetry is enableduser_pref("toolkit.telemetry.unifiedIsOptIn", true); // (hidden pref)

// 0331: remove url of server telemetry pings are sent touser_pref("toolkit.telemetry.server", "");

// 0332: disable archiving pings locally - irrelevant if toolkit.telemetry.unified is falseuser_pref("toolkit.telemetry.archive.enabled", false);

// 0333a: disable health reportuser_pref("datareporting.healthreport.uploadEnabled", false);user_pref("datareporting.healthreport.documentServerURI", ""); // (hidden pref)user_pref("datareporting.healthreport.service.enabled", false); // (hidden pref)

// 0333b: disable about:healthreport page (which connects to Mozilla for locale/css+js+json)// If you have disabled health reports, then this about page is useless - disable it// If you want to see what health data is present, then these must be set at defaultuser_pref("datareporting.healthreport.about.reportUrl", "data:text/plain,");

// 0334a: disable new data submission, master kill switch (FF41+)// If disabled, no policy is shown or upload takes place, ever// https://bugzilla.mozilla.org/show_bug.cgi?id=1195552user_pref("datareporting.policy.dataSubmissionEnabled", false);

// 0335: remove a telemetry clientID// if you haven't got one, be proactive and set it now for future proofinguser_pref("toolkit.telemetry.cachedClientID", "");

// 0336: disable "Heartbeat" (Mozilla user rating telemetry)// https://trac.torproject.org/projects/tor/ticket/18738user_pref("browser.selfsupport.enabled", false); // (hidden pref)user_pref("browser.selfsupport.url", "");

// 0340: disable experiments// https://wiki.mozilla.org/Telemetry/Experimentsuser_pref("experiments.enabled", false);user_pref("experiments.manifest.uri", "");user_pref("experiments.supported", false);user_pref("experiments.activeExperiment", false);

// 0341: disable Mozilla permission to silently opt you into testsuser_pref("network.allow-experiments", false);

// 0350: disable crash reportsuser_pref("breakpad.reportURL", "");

// 0351: disable sending of crash reports (FF44+)user_pref("browser.tabs.crashReporting.sendReport", false);

// 0360: disable new tab tile ads & preload & marketing junkuser_pref("browser.newtab.preload", false);user_pref("browser.newtabpage.directory.ping", "data:text/plain,");user_pref("browser.newtabpage.directory.source", "data:text/plain,");user_pref("browser.newtabpage.enabled", false);user_pref("browser.newtabpage.enhanced", false);user_pref("browser.newtabpage.introShown", true);

// 0370: disable "Snippets" (Mozilla content shown on about:home screen)// https://wiki.mozilla.org/Firefox/Projects/Firefox_Start/Snippet_Service// MUST use HTTPS - arbitrary content injected into this page via http opens up MiTM attacksuser_pref("browser.aboutHomeSnippets.updateUrl", "https://127.0.0.1");

// 0373: disable "Pocket" (third party "save for later" service) & remove urls for good measure// NOTE: Important: Remove the pocket icon from your toolbar first// https://www.gnu.gl/blog/Posts/multiple-vulnerabilities-in-pocket/user_pref("extensions.pocket.enabled", false);user_pref("extensions.pocket.api", "");user_pref("extensions.pocket.site", "");user_pref("extensions.pocket.oAuthConsumerKey", "");

// 0374: disable "social" integration// https://developer.mozilla.org/en-US/docs/Mozilla/Projects/Social_APIuser_pref("social.whitelist", "");user_pref("social.toast-notifications.enabled", false);user_pref("social.shareDirectory", "");user_pref("social.remote-install.enabled", false);user_pref("social.directories", "");user_pref("social.share.activationPanelEnabled", false);user_pref("social.enabled", false); // (hidden pref)

// 0375: disable "Reader View"user_pref("reader.parse-on-load.enabled", false);

// 0376: disable FlyWeb, a set of APIs for advertising and discovering local-area web servers// https://wiki.mozilla.org/FlyWeb// https://www.ghacks.net/2016/07/26/firefox-flyweb/user_pref("dom.flyweb.enabled", false);

// 0380: disable syncuser_pref("services.sync.enabled", false); // (hidden pref)

0400: QUIET FOX [PART 2]

user_pref("ghacks_user.js.parrot", "0400 syntax error: the parrot's passed on!");

// 0401: DON'T disable extension blocklist, but sanitize blocklist url - SECURITY// It now includes updates for "revoked certificates" - security trumps privacy here// https://blog.mozilla.org/security/2015/03/03/revoking-intermediate-certificates-introducing-onecrl// https://trac.torproject.org/projects/tor/ticket/16931user_pref("extensions.blocklist.enabled", true);user_pref("extensions.blocklist.url", "https://blocklist.addons.mozilla.org/blocklist/3/%APP_ID%/%APP_VERSION%/");

// 0402: disable/enable various Kinto blocklist updates (FF50+)// What is Kinto?: https://wiki.mozilla.org/Firefox/Kinto#Specifications// As FF transitions to Kinto, the blocklists have been broken down (more could be added). These contain// block entries for certs to be revoked, add-ons and plugins to be disabled, and gfx environments that// cause problems or crashes. Here you can remove the collection name to prevent each specific list updatinguser_pref("services.blocklist.update_enabled", true);user_pref("services.blocklist.signing.enforced", true);user_pref("services.blocklist.onecrl.collection", "certificates"); // Revoked certificatesuser_pref("services.blocklist.addons.collection", "addons");user_pref("services.blocklist.plugins.collection", ""); // I have no pluginsuser_pref("services.blocklist.gfx.collection", ""); // I have gfx hw acceleration disabled

// 0410: disable safe browsing// I have redesigned this sub-section to differentiate between "real-time"/"user initiated"// data being sent to Google from all other settings such as using local blocklists/whitelists// and updating those lists. There SHOULD be NO privacy issues here. Even *IF* an URL was sent// to Google, they swear it is anonymized and only used to flag malicious sites/activity. Firefox// also takes measures such as striping out identifying parameters and storing safe browsing// cookies in a separate jar. (#Turn on browser.safebrowsing.debug to monitor this activity)// To use safebrowsing but not "leak" binary download info to Google, only use 0410e and 0410f// #Required reading: https://feeding.cloud.geek.nz/posts/how-safe-browsing-works-in-firefox/// https://wiki.mozilla.org/Security/Safe_Browsing

// 0410a: disable "Block dangerous and deceptive content" This setting is under Options>Security// in FF47 and under this is was titled "Block reported web forgeries"// this covers deceptive sites such as phishing and social engineeringuser_pref("browser.safebrowsing.malware.enabled", false);user_pref("browser.safebrowsing.phishing.enabled", false); // (FF50+)

// 0410b: disable "Block dangerous downloads" This setting is under Options>Security// in FF47 and under this was titled "Block reported attack sites"// this covers malware and PUPs (potentially unwanted programs)user_pref("browser.safebrowsing.downloads.enabled", false);// disable "Warn me about unwanted and uncommon software" Also under Options>Security (FF48+)user_pref("browser.safebrowsing.downloads.remote.block_potentially_unwanted", false);user_pref("browser.safebrowsing.downloads.remote.block_uncommon", false);// yet more prefs added (FF49+)user_pref("browser.safebrowsing.downloads.remote.block_dangerous", false);user_pref("browser.safebrowsing.downloads.remote.block_dangerous_host", false);

// 0410c: disable Google safebrowsing downloads, updatesuser_pref("browser.safebrowsing.provider.google.updateURL", ""); // update google listsuser_pref("browser.safebrowsing.provider.google.gethashURL", ""); // list hash checkuser_pref("browser.safebrowsing.provider.google4.updateURL", ""); // (FF50+)user_pref("browser.safebrowsing.provider.google4.gethashURL", ""); // (FF50+)

// 0410d: disable mozilla safebrowsing downloads, updates// NOTE: These two prefs are also used for Tracking Protection (see 0420)user_pref("browser.safebrowsing.provider.mozilla.gethashURL", ""); // resolves hash conflictsuser_pref("browser.safebrowsing.provider.mozilla.updateURL", ""); // update FF lists

// 0410e: disable binaries NOT in local lists being checked by Google (real-time checking)user_pref("browser.safebrowsing.downloads.remote.enabled", false);user_pref("browser.safebrowsing.downloads.remote.url", "");

// 0410f: disable reporting URLsuser_pref("browser.safebrowsing.provider.google.reportURL", "");user_pref("browser.safebrowsing.reportMalwareMistakeURL", "");user_pref("browser.safebrowsing.reportPhishMistakeURL", "");user_pref("browser.safebrowsing.reportPhishURL", "");user_pref("browser.safebrowsing.provider.google4.reportURL", ""); // (FF50+)

// 0410g: show=true or hide=false the 'ignore this warning' on Safe Browsing warnings which// when clicked bypasses the block for that session. This is a means for admins to enforce SB// https://bugzilla.mozilla.org/show_bug.cgi?id=1226490// tests: see APPENDIX A: TEST SITES - Section 06// user_pref("browser.safebrowsing.allowOverride", true);

// 0420: disable tracking protection// There SHOULD be NO privacy concerns here, but you are better off using an extension such as// uBlock Origin which is not decided by a third party (disconnect) and is far more effective// (when used correctly). NOTE: There are two prefs (see 0410d) shared with Safe Browsing// https://wiki.mozilla.org/Security/Tracking_protection// https://support.mozilla.org/en-US/kb/tracking-protection-firefoxuser_pref("privacy.trackingprotection.enabled", false); // all windows pref (not just private)user_pref("privacy.trackingprotection.pbmode.enabled", false); // private browsing pref

// 0421: enable more Tracking Protection choices under Options>Privacy>Use Tracking Protectionuser_pref("privacy.trackingprotection.ui.enabled", true);

// 0430: disable SSL Error Reporting - PRIVACY// https://gecko.readthedocs.org/en/latest/browser/base/sslerrorreport/preferences.htmluser_pref("security.ssl.errorReporting.automatic", false);user_pref("security.ssl.errorReporting.enabled", false);user_pref("security.ssl.errorReporting.url", "");

// 0440: disable Mozilla's blocklist for known Flash tracking/fingerprinting (48+)// If you don't have Flash, then you don't need this enabled// NOTE: if enabled, you will need to check what prefs (safebrowsing URLs etc) this uses to update// https://www.ghacks.net/2016/07/18/firefox-48-blocklist-against-plugin-fingerprinting/// https://bugzilla.mozilla.org/show_bug.cgi?id=1237198user_pref("browser.safebrowsing.blockedURIs.enabled", false);

0600: BLOCK IMPLICIT OUTBOUND [not explicitly asked for - eg clicked on]

user_pref("ghacks_user.js.parrot", "0600 syntax error: the parrot's no more!");

// 0601: disable link prefetching// https://developer.mozilla.org/en-US/docs/Web/HTTP/Link_prefetching_FAQuser_pref("network.prefetch-next", false);

// 0602: disable dns prefetching// https://www.ghacks.net/2013/04/27/firefox-prefetching-what-you-need-to-know/// https://developer.mozilla.org/en-US/docs/Web/HTTP/Controlling_DNS_prefetchinguser_pref("network.dns.disablePrefetch", true);user_pref("network.dns.disablePrefetchFromHTTPS", true); // (hidden pref)

// 0603: disable Seer/Necko// https://developer.mozilla.org/en-US/docs/Mozilla/Projects/Neckouser_pref("network.predictor.enabled", false);

// 0603a: disable more Necko/Captive Portal// https://en.wikipedia.org/wiki/Captive_portal// https://wiki.mozilla.org/Necko/CaptivePortaluser_pref("captivedetect.canonicalURL", "");user_pref("network.captive-portal-service.enabled", false); // (FF52+?)

// 0604: disable search suggestionsuser_pref("browser.search.suggest.enabled", false);

// 0605: disable link-mouseover opening connection to linked server// http://news.slashdot.org/story/15/08/14/2321202/how-to-quash-firefoxs-silent-requests// https://www.ghacks.net/2015/08/16/block-firefox-from-connecting-to-sites-when-you-hover-over-linksuser_pref("network.http.speculative-parallel-limit", 0);

// 0606: disable pings (but enforce same host in case)// http://kb.mozillazine.org/Browser.send_pings// http://kb.mozillazine.org/Browser.send_pings.require_same_hostuser_pref("browser.send_pings", false);user_pref("browser.send_pings.require_same_host", true);

// 0607: stop links launching Windows Store on Windows 8/8.1/10// https://www.ghacks.net/2016/03/25/block-firefox-chrome-windows-store/user_pref("network.protocol-handler.external.ms-windows-store", false);

// 0608: disable predictor / prefetching (FF48+)user_pref("network.predictor.enable-prefetch", false);

0800: LOCATION BAR / SEARCH / AUTO SUGGESTIONS / HISTORY / FORMS etc

user_pref("ghacks_user.js.parrot", "0800 syntax error: the parrot's ceased to be!");

// 0801: disable location bar using search - PRIVACY// don't leak typos to a search engine, give an error message insteaduser_pref("keyword.enabled", false);

// 0802: disable location bar domain guessing - PRIVACY/SECURITY// domain guessing intercepts DNS "hostname not found errors" and resends a// request (eg by adding www or .com). This is inconsistent use (eg FQDNs), does not work// via Proxy Servers (different error), is a flawed use of DNS (TLDs: why treat .com// as the 411 for DNS errors?), privacy issues (why connect to sites you didn't// intend to), can leak sensitive data (eg query strings: eg Princeton attack),// and is a security risk (eg common typos & malicious sites set up to exploit this)user_pref("browser.fixup.alternate.enabled", false);

// 0803: disable locationbar dropdown - PRIVACY (shoulder surfers,forensics/unattended browser)user_pref("browser.urlbar.maxRichResults", 0);

// 0804: display all parts of the url// why rely on just a visual clue - helps SECURITYuser_pref("browser.urlbar.trimURLs", false);

// 0805: disable URLbar autofill -ÂPRIVACY (shoulder surfers, forensics/unattended browser)// http://kb.mozillazine.org/Inline_autocompleteuser_pref("browser.urlbar.autoFill", false);user_pref("browser.urlbar.autoFill.typed", false);

// 0806: disable autocomplete - PRIVACY (shoulder surfers, forensics/unattended browser)user_pref("browser.urlbar.autocomplete.enabled", false);

A comprehensive list of Firefox privacy and security settings

// 0808: disable history suggestions - PRIVACY (shoulder surfers, forensics/unattended browser)user_pref("browser.urlbar.suggest.history", false);

// 0809: limit history leaks via enumeration (PER TAB: back/forward) - PRIVACY// This is a PER TAB session history. You still have a full history stored under all history// default=50, minimum=1=currentpage, 2 is the recommended minimum as some pages// use it as a means of referral (eg hotlinking), 4 or 6 may be more practicaluser_pref("browser.sessionhistory.max_entries", 4);

// 0810: disable css querying page history - css history leak - PRIVACY// NOTE: this has NEVER been fully "resolved": in Mozilla/docs it is stated it's only in// 'certain circumstances', also see latest comments in the bug link// https://dbaron.org/mozilla/visited-privacy// https://bugzilla.mozilla.org/show_bug.cgi?id=147777// https://developer.mozilla.org/en-US/docs/Web/CSS/Privacy_and_the_:visited_selectoruser_pref("layout.css.visited_links_enabled", false);

// 0811: disable displaying javascript in history URLs - SECURITYuser_pref("browser.urlbar.filter.javascript", true);

// 0812: disable search and form history// Under Options>Privacy> if you set Firefox to "use custom settings" there will be a// setting called "remember search and form history".// You can clear formdata on exiting Firefox (see 2803)// user_pref("browser.formfill.enable", false);

// 0813: disable saving form data on secure websites - PRIVACY (shoulder surfers etc)// For convenience & functionality, this is best left at default true.// You can clear formdata on exiting Firefox (see 2803)// user_pref("browser.formfill.saveHttpsForms", false);

// 0815: disable live search suggestions in the urlbar and toggle off the Opt-In prompt (FF41+)// Setting: Options>Privacy>Location Bar>Related searches from the default search engineuser_pref("browser.urlbar.suggest.searches", false);user_pref("browser.urlbar.userMadeSearchSuggestionsChoice", true);

// 0816: disable browsing and download history// Under Options>Privacy> if you set Firefox to "use custom settings" there will be a// setting called "remember my browsing and download history"// You can clear history and downloads on exiting Firefox (see 2803)// user_pref("places.history.enabled", false);

// 0817: disable Jumplist (Windows7+)user_pref("browser.taskbar.lists.enabled", false);user_pref("browser.taskbar.lists.frequent.enabled", false);user_pref("browser.taskbar.lists.recent.enabled", false);user_pref("browser.taskbar.lists.tasks.enabled", false);

// 0818: disable taskbar previewuser_pref("browser.taskbar.previews.enable", false);

// 0819: disable one-off searches from the addressbar (FF51+)// https://www.ghacks.net/2016/08/09/firefox-one-off-searches-address-bar/user_pref("browser.urlbar.oneOffSearches", false);

// 0820: disable search reset (about:searchreset) (FF51+)// https://www.ghacks.net/2016/08/19/firefox-51-search-restore-feature/user_pref("browser.search.reset.enabled", false);user_pref("browser.search.reset.whitelist", "");

0900: PASSWORDS

user_pref("ghacks_user.js.parrot", "0900 syntax error: the parrot's expired!");

// 0901: disable saving passwords// Options>Security>Logins>Remember logins for sites// NOTE: this does not clear any passwords already saved// user_pref("signon.rememberSignons", false);

// 0902: use a master password (recommended if you save passwords)// There are no preferences for this. It is all handled internally.// https://support.mozilla.org/en-US/kb/use-master-password-protect-stored-logins

// 0903: set how often Mozilla should ask for the master password// 0=the first time, 1=every time it's needed, 2=every n minutes (as per the next pref)// WARNING: the default is 0, author changed his settingsuser_pref("security.ask_for_password", 2);

// 0904: how often in minutes Mozilla should ask for the master password (see pref above)// in minutes, default is 30user_pref("security.password_lifetime", 5);

// 0905: disable auto-filling username & password form fields - SECURITY// can leak in cross-site forms AND be spoofed// http://kb.mozillazine.org/Signon.autofillForms// password will still be auto-filled after a user name is manually entereduser_pref("signon.autofillForms", false);

// 0906: ignore websites' autocomplete="off" (FF30+)user_pref("signon.storeWhenAutocompleteOff", true);

// 0907: force warnings for logins on non-secure (non HTTPS) pages// https://bugzilla.mozilla.org/show_bug.cgi?id=1217156user_pref("security.insecure_password.ui.enabled", true);

// 0908: When attempting to fix an entered URL, do not fix an entered password along with it// i.e do not turn ~http://user:[email protected] into ~http://user:[email protected](prefix)foo(suffix)// but instead ~http://[email protected](prefix)foo(suffix))user_pref("browser.fixup.hide_user_pass", true);

// 0909: disabling for now (FF51+)user_pref("signon.formlessCapture.enabled", false);

1000: CACHE

user_pref("ghacks_user.js.parrot", "1000 syntax error: the parrot's gone to meet 'is maker!");

// 1001: disable disk cacheuser_pref("browser.cache.disk.enable", false);user_pref("browser.cache.disk.capacity", 0);user_pref("browser.cache.disk.smart_size.enabled", false);user_pref("browser.cache.disk.smart_size.first_run", false);

// 1002: disable disk caching of SSL pages// http://kb.mozillazine.org/Browser.cache.disk_cache_ssluser_pref("browser.cache.disk_cache_ssl", false);

// 1003: disable memory cache as well IF you're REALLY paranoid// I haven't tried it, but I'm sure you'll take a performance/traffic hit// user_pref("browser.cache.memory.enable", false);

// 1004: disable offline cacheuser_pref("browser.cache.offline.enable", false);

// 1005: disable storing extra session data 0=all 1=http-only 2=none// extra session data contains contents of forms, scrollbar positions, cookies and POST datauser_pref("browser.sessionstore.privacy_level", 2);

// 1006: disable pages being stored in memory. This is not the same as memory cache.// Visited pages are stored in memory in such a way that they don't have to be// re-parsed. This improves performance when pressing back/forward.// For the sake of completeness, this option is listed for the truly paranoid.// 0=none, -1=auto (that's minus 1), or any other positive integer// http://kb.mozillazine.org/Browser.sessionhistory.max_total_viewers// user_pref("browser.sessionhistory.max_total_viewers", 0);

// 1007: disable the Session Restore service completely// WARNING: This also disables the "Recently Closed Tabs" feature// It does not affect "Recently Closed Windows" or any history.user_pref("browser.sessionstore.max_tabs_undo", 0);user_pref("browser.sessionstore.max_windows_undo", 0);

// 1008: IF you use session restore (see 1007 above), increasing the minimal interval between// two session save operations can help on older machines and some websites.// Default is 15000 (15 secs). Try 30000 (30sec), 60000 (1min) etc - your choice.// WARNING: This can also affect entries in the "Recently Closed Tabs" feature:// i.e the longer the interval the more chance a quick tab open/close won't be captured// this longer interval *MAY* affect history but I cannot replicate any history not recorded// user_pref("browser.sessionstore.interval", 30000);

// 1009: DNS cache and expiration time (default 400 and 60 - same as TBB)// user_pref("network.dnsCacheEntries", 400);// user_pref("network.dnsCacheExpiration", 60);

// 1010: disable randomized FF HTTP cache decay experiments// https://trac.torproject.org/projects/tor/ticket/13575user_pref("browser.cache.frecency_experiment", -1);

// 1011: disable permissions manager from writing to disk (requires restart)// https://bugzilla.mozilla.org/show_bug.cgi?id=967812// user_pref("permissions.memory_only", true); // (hidden pref)

// 1012: disable resuming session from crashuser_pref("browser.sessionstore.resume_from_crash", false);

1200: SSL / OCSP / CERTS / ENCRYPTION / HSTS/HPKP/HTTPS

user_pref("ghacks_user.js.parrot", "1200 syntax error: the parrot's a stiff!");

// 1201: block rc4 fallback (default is now false as of at least FF45)user_pref("security.tls.unrestricted_rc4_fallback", false);

// 1203: enable OCSP stapling// https://blog.mozilla.org/security/2013/07/29/ocsp-stapling-in-firefox/user_pref("security.ssl.enable_ocsp_stapling", true);

// 1204: reject communication with servers using old SSL/TLS - vulnerable to a MiTM attack// https://wiki.mozilla.org/Security:Renegotiation// WARNING: tested Jan 2017 - still breaks too many sites// user_pref("security.ssl.require_safe_negotiation", true);

// 1205: display warning (red padlock) for "broken security"// https://wiki.mozilla.org/Security:Renegotiationuser_pref("security.ssl.treat_unsafe_negotiation_as_broken", true);

// 1206: require certificate revocation check through OCSP protocol// This leaks information about the sites you visit to the CA (cert authority)// It's a trade-off between security (checking) and privacy (leaking info to the CA)// WARNING: Since FF44 the default is false. If set to true, this may/will cause some// site breakage. Some users have previously mentioned issues with youtube, microsoft etc// user_pref("security.OCSP.require", true);

// 1207: query OCSP responder servers to confirm current validity of certificates (default=1)// 0=disable, 1=validate only certificates that specify an OCSP service URL// 2=enable and use values in security.OCSP.URL and security.OCSP.signinguser_pref("security.OCSP.enabled", 1);

// 1208: enforce strict pinning// https://trac.torproject.org/projects/tor/ticket/16206// PKP (public key pinning) 0-disabled 1=allow user MiTM (such as your antivirus), 2=strict// WARNING: If you rely on an AV (antivirus) to protect your web browsing// by inspecting ALL your web traffic, then leave at current default =1user_pref("security.cert_pinning.enforcement_level", 2);

// 1209: control TLS versions with min and max// 1=min version of TLS 1.0, 2-min version of TLS 1.1, 3=min version of TLS 1.2 etc// WARNING: FF/chrome currently allow TLS 1.0 by default, so this is your call.// http://kb.mozillazine.org/Security.tls.version.*// https://www.ssl.com/how-to/turn-off-ssl-3-0-and-tls-1-0-in-your-browser/// user_pref("security.tls.version.min", 2);// user_pref("security.tls.version.fallback-limit", 3);// user_pref("security.tls.version.max", 4); // allow up to and including TLS 1.3

// 1210: disable 1024-DH Encryption// https://www.eff.org/deeplinks/2015/10/how-to-protect-yourself-from-nsa-attacks-1024-bit-DH// WARNING: may break obscure sites, but not major sites, which should support ECDH over DHEuser_pref("security.ssl3.dhe_rsa_aes_128_sha", false);user_pref("security.ssl3.dhe_rsa_aes_256_sha", false);

// 1211: disable or limit SHA-1// 0 = all SHA1 certs are allowed// 1 = all SHA1 certs are blocked (including perfectly valid ones from 2015 and earlier)// 2 = deprecated option that now maps to 1// 3 = only allowed for locally-added roots (e.g. anti-virus)// 4 = only allowed for locally-added roots or for certs in 2015 and earlier// WARNING: when disabled, some man-in-the-middle devices (eg security scanners and antivirus// products, are failing to connect to HTTPS sites. SHA-1 will eventually become obsolete.// https://blog.mozilla.org/security/2016/10/18/phasing-out-sha-1-on-the-public-web/// https://github.com/pyllyukko/user.js/issues/194#issuecomment-256509998user_pref("security.pki.sha1_enforcement_level", 1);

// 1212: disable SSL session tracking (36+)// SSL session IDs speed up HTTPS connections (no need to renegotiate) and last for 48hrs.// Since the ID is unique, web servers can (and do) use it for tracking. If set to true,// this disables sending SSL3 Session IDs and TLS Session Tickets to prevent session tracking// WARNING: This will slow down TLS connections (personally I don't notice it at all)// https://tools.ietf.org/html/rfc5077// https://bugzilla.mozilla.org/show_bug.cgi?id=967977user_pref("security.ssl.disable_session_identifiers", true); // (hidden pref)

// 1213: disable 3DES (effective key size < 128)// https://en.wikipedia.org/wiki/3des#Security// http://en.citizendium.org/wiki/Meet-in-the-middle_attack// http://www-archive.mozilla.org/projects/security/pki/nss/ssl/fips-ssl-ciphersuites.htmluser_pref("security.ssl3.rsa_des_ede3_sha", false);

// 1214: disable 128 bitsuser_pref("security.ssl3.ecdhe_ecdsa_aes_128_sha", false);user_pref("security.ssl3.ecdhe_rsa_aes_128_sha", false);

// 1215: disable Microsoft Family Safety cert (Windows 8.1)// 0: disable detecting Family Safety mode and importing the root// 1: only attempt to detect Family Safety mode (don't import the root)// 2: detect Family Safety mode and import the rootuser_pref("security.family_safety.mode", 0);

// 1216: disable insecure active content on https pages - mixed contentuser_pref("security.mixed_content.block_active_content", true);

// 1217: disable insecure passive content (such as images) on https pages - mixed context// current default=false, leave it this way as too many sites break visually// user_pref("security.mixed_content.block_display_content", true);

// 1218: disable HSTS Priming (FF51+)// RISKS: formerly blocked mixed-content may load, may cause noticeable delays eg requests//Âtime out, requests may not be handled well by servers, possible fingerprinting// https://bugzilla.mozilla.org/show_bug.cgi?id=1246540#c145user_pref("security.mixed_content.send_hsts_priming", false);user_pref("security.mixed_content.use_hsts", false);

// 1219: disable HSTS preload list// recommended enabled, unless you fully understand the risks and trade-offs// user_pref("network.stricttransportsecurity.preloadlist", false);

// 1220: disable intermediate certificate caching (fingerprinting attack vector)// NOTE: This affects login/cert/key dbs. AFAIK the only effect is all active logins start anew// per session. This may be better handled under FPI (ticket 1323644, part of Tor Uplift)// https://bugzilla.mozilla.org/show_bug.cgi?id=1334485 // related bug// https://bugzilla.mozilla.org/show_bug.cgi?id=1216882 // related bug (see comment 9)// user_pref("security.nocertdb", true); // (hidden pref)

1400: FONTS

user_pref("ghacks_user.js.parrot", "1400 syntax error: the parrot's bereft of life!");

// 1401: disable websites downloading their own fonts (0=block, 1=allow)// This setting is under Options>Content>Font & Colors>Advanced>Allow pages to choose...// If you disallow fonts, this drastically limits/reduces font enumeration (by JS) which// is a high entropy fingerprinting vector.// WARNING: Disabling fonts can uglify the web a fair bit.user_pref("browser.display.use_document_fonts", 0);

// 1402: allow icon fonts (glyphs) (FF41+)user_pref("gfx.downloadable_fonts.enabled", true);

// 1403: disable rendering of SVG OpenType fonts// https://wiki.mozilla.org/SVGOpenTypeFonts - iSECPartnersReport recommends to disable thisuser_pref("gfx.font_rendering.opentype_svg.enabled", false);

// 1404: use more legible default fonts// WARNING: These are the author's settings, comment out if you do not require them// Been using this for over a year, it really grows on youuser_pref("font.name.serif.x-unicode", "Georgia");user_pref("font.name.serif.x-western", "Georgia"); // default Times New Romanuser_pref("font.name.sans-serif.x-unicode", "Arial");user_pref("font.name.sans-serif.x-western", "Arial");Â// default Arialuser_pref("font.name.monospace.x-unicode", "Lucida Console");user_pref("font.name.monospace.x-western", "Lucida Console"); // default Courier New

// 1405: disable woff2user_pref("gfx.downloadable_fonts.woff2.enabled", false);

// 1406: disable CSS Font Loading API// WARNING: Disabling fonts can uglify the web a fair bit.user_pref("layout.css.font-loading-api.enabled", false);

// 1407: remove special underline handling for a few fonts which you will probably never use.// Any of these fonts on your system can be enumerated for fingerprinting. Requires restart.// http://kb.mozillazine.org/Font.blacklist.underline_offsetuser_pref("font.blacklist.underline_offset", "");

// 1408: disable graphite which FF49 turned back on by default// In the past it had security issues - need citationuser_pref("gfx.font_rendering.graphite.enabled", false);

1600: HEADERS / REFERERS

Required reading: https://feeding.cloud.geek.nz/posts/tweaking-referrer-for-privacy-in-firefox/

user_pref("ghacks_user.js.parrot", "1600 syntax error: the parrot rests in peace!");// 1601: disable referer from an SSL Website// to be deprecated in FF52+? - https://bugzilla.mozilla.org/show_bug.cgi?id=1308725user_pref("network.http.sendSecureXSiteReferrer", false);

// 1602: DNT HTTP header - essentially USELESS - default is off. I recommend off.// NOTE: "Options>Privacy>Tracking>Request that sites not track you"// if you use NoScript MAKE SURE to set your noscript.doNotTrack.enabled to match// http://kb.mozillazine.org/Privacy.donottrackheader.value (pref required since FF21+)// user_pref("privacy.donottrackheader.enabled", true);// user_pref("privacy.donottrackheader.value", 1); // (hidden pref)

// 1603: referer, WHEN to send// 0=never, 1=send only when links are clicked, 2=for links and images (default)// user_pref("network.http.sendRefererHeader", 2);

// 1604: referer, SPOOF or NOT (default=false)// user_pref("network.http.referer.spoofSource", false);

// 1605: referer, HOW to handle cross origins// 0=always (default), 1=only if base domains match, 2=only if hosts match// user_pref("network.http.referer.XOriginPolicy", 0);

// 1606: referer, WHAT to send (limit the information)// 0=send full URI (default), 1=scheme+host+port+path, 2=scheme+host+port// user_pref("network.http.referer.trimmingPolicy", 0);

1800: PLUGINS

user_pref("ghacks_user.js.parrot", "1800 syntax error: the parrot's pushing up daisies!");

// 1801: set default plugin state (i.e new plugins on discovery) to never activate// 0=disabled, 1=ask to activate, 2=active - you can override individual plugins

user_pref("plugin.default.state", 0);user_pref("plugin.defaultXpi.state", 0);

// 1802: enable click to play and set to 0 minutesuser_pref("plugins.click_to_play", true);user_pref("plugin.sessionPermissionNow.intervalInMinutes", 0);

// 1802a: make sure a plugin is in a certain state: 0=deactivated 1=ask 2=enabled (Flash example)// you can set all these plugin.state's via Add-ons>Plugins or search for plugin.state in about:config// NOTE: you can still over-ride individual sites eg youtube via site permissions// https://www.ghacks.net/2013/07/09/how-to-make-sure-that-a-firefox-plugin-never-activates-again/// user_pref("plugin.state.flash", 0);

// 1804: disable plugins using external/untrusted scripts with XPCOM or XPConnectuser_pref("security.xpconnect.plugin.unrestricted", false);

// 1805: disable scanning for plugins// http://kb.mozillazine.org/Plugin_scanning// plid.all = whether to scan the directories specified in the Windows registry for PLIDs// includes: RealPlayer, Next-Generation Java Plug-In, Adobe Flash, Antivirus etc// WARNING: The author turned off plugins, try it one day. You are not missing much.user_pref("plugin.scan.plid.all", false);

// 1806: Acrobat, Quicktime, WMP are handled separately from 1805 above.// The string refers to min version number alloweduser_pref("plugin.scan.Acrobat", "99999");user_pref("plugin.scan.Quicktime", "99999");user_pref("plugin.scan.WindowsMediaPlayer", "99999");

// 1807: disable auto-play of HTML5 media// WARNING: This may break youtube video playback (and probably other sites). If you block// autoplay but occasionally would like a toggle button, try the following add-on// https://addons.mozilla.org/en-US/firefox/addon/autoplay-toggleuser_pref("media.autoplay.enabled", false);

// 1808: disable audio auto-play in non-active tabs (FF51+)// https://www.ghacks.net/2016/11/14/firefox-51-blocks-automatic-audio-playback-in-non-active-tabs/user_pref("media.block-autoplay-until-in-foreground", true);

// 1820: disable all GMP (Gecko Media Plugins)// https://wiki.mozilla.org/GeckoMediaPluginsuser_pref("media.gmp-provider.enabled", false);user_pref("media.gmp.trial-create.enabled", false);

// 1825: disable widevine CDMuser_pref("media.gmp-widevinecdm.visible", false);user_pref("media.gmp-widevinecdm.enabled", false);user_pref("media.gmp-widevinecdm.autoupdate", false);

// 1830: disable all DRM content (EME: Encryption Media Extension)user_pref("media.eme.enabled", false); // Options>Content>Play DRM Contentuser_pref("browser.eme.ui.enabled", false); // hides "Play DRM Content" checkbox, restart requireduser_pref("media.eme.apiVisible", false); // block websites detecting DRM is disabled

// 1840: disable the OpenH264 Video Codec by Cisco to "Never Activate"// This is the bundled codec used for video chat in WebRTC// Disable pings to the external update/download serveruser_pref("media.gmp-gmpopenh264.enabled", false); // (hidden pref)user_pref("media.gmp-gmpopenh264.autoupdate", false);user_pref("media.gmp-manager.url", "data:text/plain,");

// 1850: disable the Adobe EME "Primetime CDM" (Content Decryption Module)// https://trac.torproject.org/projects/tor/ticket/16285user_pref("media.gmp-eme-adobe.enabled", false);user_pref("media.gmp-eme-adobe.visible", false);user_pref("media.gmp-eme-adobe.autoupdate", false);

2000: MEDIA / CAMERA / MIKE

user_pref("ghacks_user.js.parrot", "2000 syntax error: the parrot's snuffed it!");

// 2001: disable WebRTC// https://www.privacytools.io/#webrtcuser_pref("media.peerconnection.enabled", false);user_pref("media.peerconnection.use_document_iceservers", false);user_pref("media.peerconnection.video.enabled", false);user_pref("media.peerconnection.identity.enabled", false);user_pref("media.peerconnection.identity.timeout", 1);user_pref("media.peerconnection.turn.disable", true);// disable video capability for WebRTCuser_pref("media.navigator.video.enabled", false);

// 2001a: pref which improves the WebRTC IP Leak issue, as opposed to completely// disabling WebRTC. You still need to enable WebRTC for this to be applicable (FF42+)// https://wiki.mozilla.org/Media/WebRTC/Privacyuser_pref("media.peerconnection.ice.default_address_only", true); // (FF41-FF50)user_pref("media.peerconnection.ice.no_host", true); // (FF51+)

// 2010: disable WebGL, force bare minimum feature set if used & disable WebGL extensions// http://www.contextis.com/resources/blog/webgl-new-dimension-browser-exploitation/// https://security.stackexchange.com/questions/13799/is-webgl-a-security-concernuser_pref("webgl.disabled", true);user_pref("pdfjs.enableWebGL", false);user_pref("webgl.min_capability_mode", true);user_pref("webgl.disable-extensions", true);user_pref("webgl.disable-fail-if-major-performance-caveat", true);

// 2011: don't make WebGL debug info available to websites// https://bugzilla.mozilla.org/show_bug.cgi?id=1171228// https://developer.mozilla.org/en-US/docs/Web/API/WEBGL_debug_renderer_infouser_pref("webgl.enable-debug-renderer-info", false);

// 2012: two more webgl preferences (FF51+)user_pref("webgl.dxgl.enabled", false);user_pref("webgl.enable-webgl2", false);

// 2021: disable speech recognitionuser_pref("media.webspeech.recognition.enable", false);user_pref("media.webspeech.synth.enabled", false);

// 2022: disable screensharinguser_pref("media.getusermedia.screensharing.enabled", false);user_pref("media.getusermedia.screensharing.allowed_domains", "");user_pref("media.getusermedia.screensharing.allow_on_old_platforms", false);user_pref("media.getusermedia.browser.enabled", false);user_pref("media.getusermedia.audiocapture.enabled", false);

// 2023: disable camera stuffuser_pref("camera.control.face_detection.enabled", false);

// 2024: enable/disable MSE (Media Source Extensions)// https://www.ghacks.net/2014/05/10/enable-media-source-extensions-firefox/user_pref("media.mediasource.enabled", true);user_pref("media.mediasource.mp4.enabled", true);user_pref("media.mediasource.webm.audio.enabled", true);user_pref("media.mediasource.webm.enabled", true);

// 2025: enable/disable various media types - end user personal choice// WARNING: this is the author's settings, choose your ownuser_pref("media.mp4.enabled", true);user_pref("media.flac.enabled", true); // (FF51+)user_pref("media.ogg.enabled", false);user_pref("media.ogg.flac.enabled", false); // (FF51+)user_pref("media.opus.enabled", false);user_pref("media.raw.enabled", false);user_pref("media.wave.enabled", false);user_pref("media.webm.enabled", true);user_pref("media.wmf.enabled", true); // https://www.youtube.com/html5 - for the two H.264 entries

// 2026: disable canvas capture stream// https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/captureStreamuser_pref("canvas.capturestream.enabled", false);

// 2027: disable camera image capture// https://trac.torproject.org/projects/tor/ticket/16339user_pref("dom.imagecapture.enabled", false);

// 2028: disable offscreen canvas// https://developer.mozilla.org/en-US/docs/Web/API/OffscreenCanvasuser_pref("gfx.offscreencanvas.enabled", false);

UI MEDDLING

user_pref("ghacks_user.js.parrot", "2200 syntax error: the parrot's 'istory!");

// 2201: disable website control over right click context menu// WARNING: This will break some sites eg Dropbox, Google Docs? gmail?user_pref("dom.event.contextmenu.enabled", false);

// 2202: UI SPOOFING: disable scripts hiding or disabling the following on new windowsuser_pref("dom.disable_window_open_feature.location", true);user_pref("dom.disable_window_open_feature.menubar", true);user_pref("dom.disable_window_open_feature.resizable", true);user_pref("dom.disable_window_open_feature.status", true);user_pref("dom.disable_window_open_feature.toolbar", true);

// 2203: POPUP windows - prevent or allow javascript UI meddlinguser_pref("dom.disable_window_flip", true); // window z-orderuser_pref("dom.disable_window_move_resize", true);user_pref("dom.disable_window_open_feature.close", true);user_pref("dom.disable_window_open_feature.minimizable", true);user_pref("dom.disable_window_open_feature.personalbar", true); //bookmarks toolbaruser_pref("dom.disable_window_open_feature.titlebar", true);user_pref("dom.disable_window_status_change", true);user_pref("dom.allow_scripts_to_close_windows", false);

// 2204: disable links opening in a new window// https://trac.torproject.org/projects/tor/ticket/9881// test url: https://people.torproject.org/~gk/misc/entire_desktop.html// You can still right click a link and select open in a new window// This is to stop malicious window sizes and screen res leaks etc in conjunction// with 2203 dom.disable_window_move_resize=true | 2418 full-screen-api.enabled=false// user_pref("browser.link.open_newwindow.restriction", 0);

2300: SERVICE WORKERS

user_pref("ghacks_user.js.parrot", "2300 syntax error: the parrot's off the twig!");

// 2301: disable workers API and service workers API// https://developer.mozilla.org/en-US/docs/Web/API/Worker// https://developer.mozilla.org/en-US/docs/Web/API/ServiceWorker_API// https://www.ghacks.net/2016/03/02/manage-service-workers-in-firefox-and-chrome/// WARNING: WILL break sites as this gains traction: eg mega.nz requires workersuser_pref("dom.workers.enabled", false);user_pref("dom.serviceWorkers.enabled", false);

// 2302: disable service workers cache and cache storageuser_pref("dom.caches.enabled", false);

// 2303: disable push notifications (FF44+) [requires serviceWorkers to be enabled]// web apps can receive messages pushed to them from a server, whether or// not the web app is in the foreground, or even currently loaded// https://developer.mozilla.org/en/docs/Web/API/Push_API// WARNING: may affect social media sites like Twitteruser_pref("dom.push.enabled", false);user_pref("dom.push.connection.enabled", false);user_pref("dom.push.serverURL", "");user_pref("dom.push.userAgentID", "");

// 2304: disable web/push notifications// https://developer.mozilla.org/en-US/docs/Web/API/notification// NOTE: you can still override individual domains under site permissions (FF44+)// WARNING: may affect social media sites like Twitteruser_pref("dom.webnotifications.enabled", false);user_pref("dom.webnotifications.serviceworker.enabled", false);

2400: DOM & JAVASCRIPT

user_pref("ghacks_user.js.parrot", "2400 syntax error: the parrot's kicked the bucket!");

// 2402: disable website access to clipboard events/content// https://www.ghacks.net/2014/01/08/block-websites-reading-modifying-clipboard-contents-firefox/// WARNING: This will break some sites functionality such as pasting into Facebook// this applies to onCut, onCopy, onPaste events - i.e is you have to interact with// the website for it to look at the clipboarduser_pref("dom.event.clipboardevents.enabled", false);

// 2403: disable clipboard commands (cut/copy) from "non-priviledged" content// this disables document.execCommand("cut"/"copy") to protect your clipboard// https://bugzilla.mozilla.org/show_bug.cgi?id=1170911user_pref("dom.allow_cut_copy", false); // (hidden pref)

// 2404: disable JS storing data permanently// If you block indexedDB but would like a toggle button, try the following add-on// https://addons.mozilla.org/en-US/firefox/addon/disable-indexeddb/// This setting WAS under about:permissions>All Sites>Maintain Offline Storage// NOTE: about:permissions is no longer available since FF46 but you can still override// individual domains: use info icon in urlbar etc or right click on a web page>view page info// WARNING: If set as false (disabled), this WILL break some [old] add-ons and DOES break// a lot of sites' functionality. Applies to websites, add-ons and session data.user_pref("dom.indexedDB.enabled", false);

// 2405: https://wiki.mozilla.org/WebAPI/Security/WebTelephonyuser_pref("dom.telephony.enabled", false);

// 2410: disable User Timing API// https://trac.torproject.org/projects/tor/ticket/16336user_pref("dom.enable_user_timing", false);

// 2411: disable resource/navigation timinguser_pref("dom.enable_resource_timing", false);

// 2412: disable timing attacks - javascript performance fingerprinting// https://wiki.mozilla.org/Security/Reviews/Firefox/NavigationTimingAPIuser_pref("dom.enable_performance", false);

// 2414: disable shaking the screenuser_pref("dom.vibrator.enabled", false);

// 2415: max popups from a single non-click event - default is 20!user_pref("dom.popup_maximum", 3);

// 2415b: limit events that can cause a popup// default is "change click dblclick mouseup notificationclick reset submit touchend"// WARNING: Author killed all methods but does this with Popup Blocker Ultimate// in Strict mode with whitelist. Or you can allow all but blacklist. Either way,// Popup Blocker Ultimate overwrites this pref with a blank (or allows everything!).// http://kb.mozillazine.org/Dom.popup_allowed_eventsuser_pref("dom.popup_allowed_events", "click dblclick");

// 2416: disable idle observationuser_pref("dom.idle-observers-api.enabled", false);

// 2418: disable full-screen API// This setting WAS under about:permissions>All Sites>Fullscreen// NOTE: about:permissions is no longer available since FF46 but you can still override// individual domains: use info icon in urlbar etc or right click on a web page>view page info// set to false=block, set to true=askuser_pref("full-screen-api.enabled", false);

// 2420: disable support for asm.js ( http://asmjs.org/ )// https://www.mozilla.org/en-US/security/advisories/mfsa2015-29/// https://www.mozilla.org/en-US/security/advisories/mfsa2015-50/// https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-2712user_pref("javascript.options.asmjs", false);

// 2421: in addition to 2420, these settings will help harden JS against exploits such as CVE-2015-0817// https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-0817// WARNING: causes the odd site issue and there is also a performance loss// Update: Jan-2017: commented out for now, as performance gains outweigh extra security// user_pref("javascript.options.ion", false);// user_pref("javascript.options.baselinejit", false);

// 2425: disable ArchiveAPI i.e reading content of archives, such as zip files, directly// in the browser, through DOM file objects. Default is false.user_pref("dom.archivereader.enabled", false);

// 2450: force FF to tell you if a website asks to store data for offline use// https://support.mozilla.org/en-US/questions/1098540// https://bugzilla.mozilla.org/show_bug.cgi?id=959985user_pref("offline-apps.allow_by_default", false);// Options>Advanced>Network>Tell me when a website asks to store data for offline useuser_pref("browser.offline-apps.notify", true);// change size of warning quota for offline cache (default 51200)// Offline cache is only used in rare cases to store data locally. FF will store small amounts// (default <50MB) of data in the offline (application) cache without asking for permission.// user_pref("offline-apps.quota.warn", 51200);

2500: HARDWARE FINGERPRINTING

user_pref("ghacks_user.js.parrot", "2500 syntax error: the parrot's shuffled off 'is mortal coil!");

// 2501: disable gamepad API - USB device ID enumeration// https://trac.torproject.org/projects/tor/ticket/13023user_pref("dom.gamepad.enabled", false);

// 2502: disable Battery Status API. Initially a Linux issue (high precision readout) that is now fixed.// However, it is still another metric for fingerprinting, used to raise entropy.// eg: do you have a battery or not, current charging status, charge level, times remaining etc// http://techcrunch.com/2015/08/04/battery-attributes-can-be-used-to-track-web-users/// https://bugzilla.mozilla.org/show_bug.cgi?id=1124127// https://www.w3.org/TR/battery-status/// https://www.theguardian.com/technology/2016/aug/02/battery-status-indicators-tracking-online// NOTE: From FF52+ Battery Status API is only available in chrome/privileged code.// https://bugzilla.mozilla.org/show_bug.cgi?id=1313580user_pref("dom.battery.enabled", false);

// 2503: disable giving away network info// eg bluetooth, cellular, ethernet, wifi, wimax, other, mixed, unknown, none// https://developer.mozilla.org/en-US/docs/Web/API/Network_Information_API// https://wicg.github.io/netinfo/// https://bugzilla.mozilla.org/show_bug.cgi?id=960426user_pref("dom.netinfo.enabled", false);

// 2504: disable virtual reality devices// https://developer.mozilla.org/en-US/docs/Web/API/WebVR_APIuser_pref("dom.vr.enabled", false);user_pref("dom.vr.oculus.enabled", false);user_pref("dom.vr.osvr.enabled", false); // (FF49+)user_pref("dom.vr.openvr.enabled", false); // (FF51+)

// 2505: disable media device enumeration (FF29+)// NOTE: media.peerconnection.enabled should also be set to false (see 2001)// https://wiki.mozilla.org/Media/getUserMedia// https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/enumerateDevicesuser_pref("media.navigator.enabled", false);

// 2506: disable video statistics - JS performance fingerprinting/ https://trac.torproject.org/projects/tor/ticket/15757user_pref("media.video_stats.enabled", false);

// 2507: disable keyboard fingerprinting (FF38+) (physical keyboards)// The Keyboard API allows tracking the "read parameter" of pressed keys in forms on// web pages. These parameters vary between types of keyboard layouts such as QWERTY,// AZERTY, Dvorak, and between various languages, eg German vs English.// WARNING: Don't use if Android + physical keyboard// UPDATE: This MAY be incorporated better into the Tor Uplift project (see 2699)// https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/code// https://www.privacy-handbuch.de/handbuch_21v.htmuser_pref("dom.keyboardevent.code.enabled", false);user_pref("dom.beforeAfterKeyboardEvent.enabled", false);user_pref("dom.keyboardevent.dispatch_during_composition", false);

// 2508: disable graphics fingerprinting (the loss of hardware acceleration is negligible)// These prefs are under Options>Advanced>General>Use hardware acceleration when available// NOTE: changing this option changes BOTH these preferences// https://wiki.mozilla.org/Platform/GFX/HardwareAcceleration// WARNING: This changes text rendering (fonts will look different)// If you watch a lot of video, this will impact performanceuser_pref("gfx.direct2d.disabled", true);user_pref("layers.acceleration.disabled", true);

// 2509: disable touch events// https://developer.mozilla.org/en-US/docs/Web/API/Touch_events// https://trac.torproject.org/projects/tor/ticket/10286// fingerprinting attack vector - leaks screen res & actual screen coordinates// WARNING: If you use touch eg Win8/10 Metro/Smartphone reset this to defaultuser_pref("dom.w3c_touch_events.enabled", 0);

// 2510: disable Web Audio API (FF51+)// https://bugzilla.mozilla.org/show_bug.cgi?id=1288359user_pref("dom.webaudio.enabled", false);

// 2511: disable MediaDevices change detection (FF51+) (enabled by default starting FF52+)// https://developer.mozilla.org/en-US/docs/Web/Events/devicechange// https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/ondevicechangeuser_pref("media.ondevicechange.enabled", false);

2600: MISC - LEAKS / FINGERPRINTING / PRIVACY / SECURITY

user_pref("ghacks_user.js.parrot", "2600 syntax error: the parrot's run down the curtain!");

// 2601: disable sending additional analytics to web servers// https://developer.mozilla.org/en-US/docs/Web/API/navigator.sendBeaconuser_pref("beacon.enabled", false);

// 2602: CIS 2.3.2 disable downloading on desktopuser_pref("browser.download.folderList", 2);

// 2603: always ask the user where to download - enforce user interaction for securityuser_pref("browser.download.useDownloadDir", false);

// 2604: https://bugzil.la/238789#c19user_pref("browser.helperApps.deleteTempFileOnExit", true);

// 2605: don't integrate activity into windows recent documentsuser_pref("browser.download.manager.addToRecentDocs", false);

// 2606: disable hiding mime types (Options>Applications) not associated with a pluginuser_pref("browser.download.hide_plugins_without_extensions", false);

// 2607: disable page thumbnail collection// look in profile/thumbnails directory - you may want to clean that outuser_pref("browser.pagethumbnails.capturing_disabled", true); // (hidden pref)

// 2608: disable JAR from opening Unsafe File Typesuser_pref("network.jar.open-unsafe-types", false);

// 2611: disable WebIDE to prevent remote debugging and add-on downloads// https://trac.torproject.org/projects/tor/ticket/16222user_pref("devtools.webide.autoinstallADBHelper", false);user_pref("devtools.webide.autoinstallFxdtAdapters", false);user_pref("devtools.debugger.remote-enabled", false);user_pref("devtools.webide.enabled", false);

// 2612: disable SimpleServiceDiscovery - which can bypass proxy settings - eg Roku// https://trac.torproject.org/projects/tor/ticket/16222user_pref("browser.casting.enabled", false);user_pref("gfx.layerscope.enabled", false);

// 2613: disable device sensor API - fingerprinting vector// https://trac.torproject.org/projects/tor/ticket/15758user_pref("device.sensors.enabled", false);

// 2614: disable SPDY as it can contain identifiers// https://www.torproject.org/projects/torbrowser/design/#identifier-linkability (no. 10)user_pref("network.http.spdy.enabled", false);user_pref("network.http.spdy.enabled.deps", false);

// 2615: disable http2 for now as welluser_pref("network.http.spdy.enabled.http2", false);

// 2617: disable pdf.js as an option to preview PDFs within Firefox// see mime-types under Options>Applications) - EXPLOIT risk// Enabling this (set to true) will change your option most likely to "Ask" or "Open with// some external pdf reader". This does NOT necessarily prevent pdf.js being used via// other means, it only removes the option. I think this should be left at default (false).// 1. It won't stop JS bypassing it. 2. Depending on external pdf viewers there is just as// much risk or more (acrobat). 3. Mozilla are very quick to patch these sorts of exploits,// they treat them as severe/critical and 4. for convenienceuser_pref("pdfjs.disabled", false);

// 2618: when using SOCKS have the proxy server do the DNS lookup - dns leak issue// http://kb.mozillazine.org/Network.proxy.socks_remote_dns// https://trac.torproject.org/projects/tor/wiki/doc/TorifyHOWTO/WebBrowsers// eg in TOR, this stops your local DNS server from knowing your Tor destination// as a remote Tor node will handle the DNS request

user_pref("network.proxy.socks_remote_dns", true);

// 2619: limit HTTP redirects (this does not control redirects with HTML meta tags or JS)// WARNING: a low setting of 5 or under will probably break some sites (eg gmail logins)// To control HTML Meta tag and JS redirects, use an add-on (eg NoRedirect). Default is 20user_pref("network.http.redirection-limit", 10);

// 2620: disable middle mouse click opening links from clipboard// https://trac.torproject.org/projects/tor/ticket/10089// http://kb.mozillazine.org/Middlemouse.contentLoadURLuser_pref("middlemouse.contentLoadURL", false);

// 2621: disable IPv6 (included for knowledge ONLY - not recommended)// This is all about covert channels such as MAC addresses being included/abused in the// IPv6 protocol for tracking. If you want to mask your IP address, this is not the way// to do it. It's 2016, IPv6 is here. Here are some old links// 2010: https://www.christopher-parsons.com/ipv6-and-the-future-of-privacy/// 2011: https://iapp.org/news/a/2011-09-09-facing-the-privacy-implications-of-ipv6// 2012: http://www.zdnet.com/article/security-versus-privacy-with-ipv6-deployment/// NOTE: It is a myth that disabling IPv6 will speed up your internet connection// http://www.howtogeek.com/195062/no-disabling-ipv6-probably-wont-speed-up-your-internet-connection// user_pref("network.dns.disableIPv6", true);// user_pref("network.http.fast-fallback-to-IPv4", true);

// 2622: ensure you have a security delay when installing add-ons (milliseconds)// default=1000, This also covers the delay in "Save" on downloading files.// http://kb.mozillazine.org/Disable_extension_install_delay_-_Firefox// http://www.squarefree.com/2004/07/01/race-conditions-in-security-dialogs/user_pref("security.dialog_enable_delay", 1000);

// 2623: ensure Strict File Origin Policy on local files// The default is true. Included for completeness// http://kb.mozillazine.org/Security.fileuri.strict_origin_policyuser_pref("security.fileuri.strict_origin_policy", true);

// 2624: enforce Subresource Integrity (SRI) (FF43+)// The default is true. Included for completeness// https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity// https://wiki.mozilla.org/Security/Subresource_Integrityuser_pref("security.sri.enable", true);

// 2625: Applications [non Tor protocol] SHOULD generate an error// upon the use of .onion and SHOULD NOT perform a DNS lookup.// https://bugzilla.mozilla.org/show_bug.cgi?id=1228457user_pref("network.dns.blockDotOnion", true);

// 2626: strip optional user agent token, default is false, included for completeness// https://developer.mozilla.org/en-US/docs/Web/HTTP/Gecko_user_agent_string_referenceuser_pref("general.useragent.compatMode.firefox", false);

// 2627: Spoof default UA & relevant (navigator) parts (also see 0204 for UA language)// NOTE: may be better handled by an extension (eg whitelisitng), try not to clash with it// NOTE: this is NOT a complete solution (feature detection, some navigator objects leak, resource URI etc)// AIM: match latest TBB settings: Windows, ESR, OS etc// WARNING: If you do not understand fingerprinting then don't use this section// test: http://browserspy.dk/browser.php//Â Â Â Â Â Âhttp://browserspy.dk/showprop.php (for buildID)//Â Â Â Â Â Âhttp://browserspy.dk/useragent.php// ==start==// A: navigator.userAgent leaks in JS, setting this also seems to break UA extension whitelisting// user_pref("general.useragent.override", "Mozilla/5.0 (Windows NT 6.1; rv:45.0) Gecko/20100101 Firefox/45.0"); // (hidden pref)// B: navigator.buildID (see gecko.buildID in about:config) reveals build time// down to the second which defeats user agent spoofing and can compromise OS etc// https://bugzilla.mozilla.org/show_bug.cgi?id=583181user_pref("general.buildID.override", "20100101"); // (hidden pref)

// C: navigator.appNameuser_pref("general.appname.override", "Netscape"); // (hidden pref)

// D: navigator.appVersionuser_pref("general.appversion.override", "5.0 (Windows)"); // (hidden pref)

// E: navigator.platform leaks in JSuser_pref("general.platform.override", "Win32"); // (hidden pref)

// F: navigator.oscpuuser_pref("general.oscpu.override", "Windows NT 6.1"); // (hidden pref)

// 2628: disable UITour backend so there is no chance that a remote page can use ituser_pref("browser.uitour.enabled", false);user_pref("browser.uitour.url", "");

// 2629: disable remote JAR files being opened, regardless of content type// https://bugzilla.mozilla.org/show_bug.cgi?id=1215235user_pref("network.jar.block-remote-files", true);

// 2650: start the browser in e10s mode (48+)// After restarting the browser, you can check whether it's enabled by visiting// about:support and checking that "Multiprocess Windows" = 1// use force-enable and extensions.e10sblocksenabling if you have add-ons// user_pref("browser.tabs.remote.autostart", true);// user_pref("browser.tabs.remote.autostart.2", true); // (FF49+)// user_pref("browser.tabs.remote.force-enable", true); // (hidden pref)// user_pref("extensions.e10sBlocksEnabling", false);

// 2651: control e10s number of container processes// https://www.ghacks.net/2016/02/15/change-how-many-processes-multi-process-firefox-uses/// https://bugzilla.mozilla.org/show_bug.cgi?id=1207306// user_pref("dom.ipc.processCount", 4);

// 2652: enable console shim warnings for extensions that don't have the flag// 'multiprocessCompatible' set to trueuser_pref("dom.ipc.shims.enabledWarnings", true);

// 2660: enforce separate content process for file://URLs (FF53+?)// https://bugzilla.mozilla.org/show_bug.cgi?id=1147911// https://www.ghacks.net/2016/11/27/firefox-53-exclusive-content-process-for-local-files/user_pref("browser.tabs.remote.separateFileUriProcess", true);

// 2662: disable "open with" in download dialog (FF50+)// This is very useful to enable when the browser is sandboxed (e.g. via AppArmor)// in such a way that it is forbidden to run external applications.// WARNING: This may interfere with some users' workflow or methods// https://bugzilla.mozilla.org/show_bug.cgi?id=1281959user_pref("browser.download.forbid_open_with", true);

// 2663: disable MathML (FF51+)// https://bugzilla.mozilla.org/show_bug.cgi?id=1173199// test: http://browserspy.dk/mathml.phpuser_pref("mathml.disabled", true);

// 2664: disable DeviceStorage API// https://wiki.mozilla.org/WebAPI/DeviceStorageAPIuser_pref("device.storage.enabled", false);

// 2665: sanitize webchannel whitelistuser_pref("webchannel.allowObject.urlWhitelist", "");

// 2666: disable HTTP Alternative Services// #comment-3970881user_pref("network.http.altsvc.enabled", false);user_pref("network.http.altsvc.oe", false);

// 2667: disable various developer tools in browser context// Devtools>Advanced Settings>Enable browser chrome and add-on debugging toolboxes// http://github.com/pyllyukko/user.js/issues/179#issuecomment-246468676user_pref("devtools.chrome.enabled", false);

// 2668: lock down allowed extension directories// https://mike.kaply.com/2012/02/21/understanding-add-on-scopes/// archived: http://archive.is/DYjAMuser_pref("extensions.enabledScopes", 1); // (hidden pref)user_pref("extensions.autoDisableScopes", 15);

// 2669: strip paths when sending URLs to PAC scripts (FF51+)// CVE-2017-5384: Information disclosure via Proxy Auto-Config (PAC)// https://bugzilla.mozilla.org/show_bug.cgi?id=1255474user_pref("network.proxy.autoconfig_url.include_path", false);

// 2670: close bypassing of CSP via image mime types (FF51+)// https://bugzilla.mozilla.org/show_bug.cgi?id=1288361user_pref("security.block_script_with_wrong_mime", true);

// 2671: disable SVG (FF53+)// https://bugzilla.mozilla.org/show_bug.cgi?id=1216893user_pref("svg.disabled", true);

2698: FIRST PARTY ISOLATION (PFI)

// 2698a: enable first party isolation pref and OriginAttribute (FF51+)// WARNING: breaks lots of cross-domain logins and site funtionality until perfected// https://bugzilla.mozilla.org/show_bug.cgi?id=1260931// 2698b: this also isolates OCSP requests by first party domain// https://bugzilla.mozilla.org/show_bug.cgi?id=1264562// user_pref("privacy.firstparty.isolate", true);

2699: TOR UPLIFT: privacy.resistFingerprinting

// 2699a: limit window.screen & CSS media queries providing large amounts of identifiable info.// POC: http://ip-check.info/?lang=en (screen, usable screen, and browser window will match)// https://bugzilla.mozilla.org/show_bug.cgi?id=418986// NOTE: does not cover everything yet - https://bugzilla.mozilla.org/show_bug.cgi?id=1216800// NOTE: this will probably make your values pretty unique until you resize or snap the// inner window width + height into standard/common resolutions (mine is at 1366x768)// To set a size, open a XUL (chrome) page (such as about:config) which is at 100% zoom, hit// Shift+F4 to open the scratchpad, type window.resizeTo(1366,768), hit Ctrl+R to run. Test// your window size, do some math, resize to allow for all the non inner window elements// test: http://browserspy.dk/screen.php// Common resolutions: http://www.rapidtables.com/web/dev/screen-resolution-statistics.htm

// 2699b: spoof screen orientation// https://bugzilla.mozilla.org/show_bug.cgi?id=1281949// 2699c: hide the contents of navigator.plugins and navigator.mimeTypes (FF50+)// https://bugzilla.mozilla.org/show_bug.cgi?id=1281963user_pref("privacy.resistFingerprinting", true); // (hidden pref)

2700: COOKIES & DOM STORAGE

user_pref("ghacks_user.js.parrot", "2700 syntax error: the parrot's joined the bleedin' choir invisible!");

// 2701: disable cookies on all sites// you can set exceptions under site permissions or use an extension (eg Cookie Controller)// 0=allow all 1=allow same host 2=disallow all 3=allow 3rd party if it already set a cookieuser_pref("network.cookie.cookieBehavior", 2);

// 2702: ensure that third-party cookies (if enabled, see above pref) are session-only// https://feeding.cloud.geek.nz/posts/tweaking-cookies-for-privacy-in-firefox/// http://kb.mozillazine.org/Network.cookie.thirdparty.sessionOnlyuser_pref("network.cookie.thirdparty.sessionOnly", true);

// 2703: set cookie lifetime policy// 0=until they expire (default), 2=until you close Firefox, 3=for n days (see next pref)// If you use custom settings for History in Options, this is the setting under// Privacy>Accept cookies from sites>Keep until // user_pref("network.cookie.lifetimePolicy", 0);

// 2704: set cookie lifetime in days (see above pref) - default is 90 days// user_pref("network.cookie.lifetime.days", 90);

// 2705: disable dom storage// WARNING: this will break a LOT of sites' functionality.// You are better off using an extension for more granular control// user_pref("dom.storage.enabled", false);

// 2706: disable Storage API (FF51+) which gives sites' code the ability to find out how much space// they can use, how much they are already using, and even control whether or not they need to// be alerted before the user agent disposes of site data in order to make room for other things.// https://developer.mozilla.org/en-US/docs/Web/API/StorageManager// https://developer.mozilla.org/en-US/docs/Web/API/Storage_APIuser_pref("dom.storageManager.enabled", false);

// 2707: clear localStorage and UUID when a WebExtension is uninstalled// NOTE: both preferences must be the same// https://developer.mozilla.org/en-US/Add-ons/WebExtensions/API/storage/local// https://bugzilla.mozilla.org/show_bug.cgi?id=1213990user_pref("extensions.webextensions.keepStorageOnUninstall", false);user_pref("extensions.webextensions.keepUuidOnUninstall", false);

2800: SHUTDOWN

user_pref("ghacks_user.js.parrot", "2800 syntax error: the parrot's bleedin' demised!");

// 2802: enable FF to clear stuff on close// This setting is under Options>Privacy>Clear history when Firefox closesuser_pref("privacy.sanitize.sanitizeOnShutdown", true);

// 2803: what to clear on shutdown// These settings are under Options>Privacy>Clear history when Firefox closes>Settings// These are the settings of the author of this user.js, chose your ownuser_pref("privacy.clearOnShutdown.cache", true);user_pref("privacy.clearOnShutdown.cookies", false);user_pref("privacy.clearOnShutdown.downloads", true);user_pref("privacy.clearOnShutdown.formdata", true);user_pref("privacy.clearOnShutdown.history", true);user_pref("privacy.clearOnShutdown.offlineApps", true);user_pref("privacy.clearOnShutdown.sessions", false); // active loginsuser_pref("privacy.clearOnShutdown.siteSettings", false);

// 2803a: include all open windows/tabs when you shutdown// user_pref("privacy.clearOnShutdown.openWindows", true);

// 2804: (to match above) - auto selection of items to delete with Ctrl-Shift-Deluser_pref("privacy.cpd.cache", true);user_pref("privacy.cpd.cookies", false);user_pref("privacy.cpd.downloads", true);user_pref("privacy.cpd.formdata", true);user_pref("privacy.cpd.history", true);user_pref("privacy.cpd.offlineApps", true);user_pref("privacy.cpd.passwords", false);user_pref("privacy.cpd.sessions", false);user_pref("privacy.cpd.siteSettings", false);

// 2804a: include all open windows/tabs when you run clear recent history// user_pref("privacy.cpd.openWindows", true);

// 2805: reset default 'Time range to clear' for 'clear recent history' (see 2804 above)// Firefox remembers your last choice. This will reset the value when you start FF.// 0=everything 1=last hour, 2=last 2 hours, 3=last 4 hours, 4=todayuser_pref("privacy.sanitize.timeSpan", 0);

3000: PERSONAL SETTINGS

user_pref("ghacks_user.js.parrot", "3000 syntax error: this is an ex-parrot!");

// 3001: disable annoying warningsuser_pref("general.warnOnAboutConfig", false);user_pref("browser.tabs.warnOnClose", false);user_pref("browser.tabs.warnOnCloseOtherTabs", false);user_pref("browser.tabs.warnOnOpen", false);

// 3001a: disable warning when a domain requests full screen// https://developer.mozilla.org/en-US/docs/Web/Guide/API/DOM/Using_full_screen_mode// user_pref("full-screen-api.warning.delay", 0);// user_pref("full-screen-api.warning.timeout", 0);

// 3002: disable closing browser with last tabuser_pref("browser.tabs.closeWindowWithLastTab", false);

// 3004: disable backspace (0 = previous page, 1 = scroll up, 2 = do nothing)user_pref("browser.backspace_action", 2);

// 3005: disable autocopy default (use extensions autocopy 2 & copy plain text 2)user_pref("clipboard.autocopy", false);

// 3007: open new windows in a new tab instead// This setting is under Options>General>Tabs// 1=current window, 2=new window, 3=most recent windowuser_pref("browser.link.open_newwindow", 3);

// 3008: disable "Do you really want to leave this site?" popups// https://support.mozilla.org/en-US/questions/1043508user_pref("dom.disable_beforeunload", true);

// 3009: turn on APZ (Async Pan/Zoom) - requires e10s// https://www.ghacks.net/2015/07/28/scrolling-in-firefox-to-get-a-lot-better-thanks-to-apz/// user_pref("layers.async-pan-zoom.enabled", true);

// 3010: enable ctrl-tab previewsuser_pref("browser.ctrlTab.previews", true);

// 3011: don't open "page/selection source" in a tab. The window used instead is cleaner// and easier to use and move around (eg developers/multi-screen).user_pref("view_source.tab", false);

// 3012: spellchecking: 0=none, 1-multi-line controls, 2=multi-line & single-line controlsuser_pref("layout.spellcheckDefault", 1);

// 3013: disable automatic "Work Offline" status// https://bugzilla.mozilla.org/show_bug.cgi?id=620472// https://developer.mozilla.org/en-US/docs/Online_and_offline_eventsuser_pref("network.manage-offline-status", false);

// 3015: disable tab animation, speed things up a littleuser_pref("browser.tabs.animate", false);

// 3016: disable fullscreeen animation. Test using F11.// Animation is smother but is annoyingly slow, while no animation can be startlinguser_pref("browser.fullscreen.animate", false);

// 3017: submenu in milliseconds. 0=instant while a small number allows// a mouse pass over menu items without any submenus alarmingly shooting outuser_pref("ui.submenuDelay", 75); // (hidden pref)

// 3018: maximum number of daily bookmark backups to keep (default is 15)user_pref("browser.bookmarks.max_backups", 2);

// 3020: FYI: urlbar click behaviour (with defaults)user_pref("browser.urlbar.clickSelectsAll", true);user_pref("browser.urlbar.doubleClickSelectsAll", false);

// 3021: FYI: tab behaviours (with defaults)// open links in a new tab immediately to the right of parent tab, not far rightuser_pref("browser.tabs.insertRelatedAfterCurrent", true);// switch to the parent tab (if it has one) on close, rather than to the adjacent right tab if// it exists or to the adjacent left tab if it doesn't. NOTE: requires browser.link.open_newwindow// set to 3 (see pref 3007). NOTE: does not apply to middle-click or Ctrl-clicking links.user_pref("browser.tabs.selectOwnerOnClose", true);

// Options>General>When I open a link in a new tab, switch to it immediately// default is unchecked = DON'T switch to it = trueuser_pref("browser.tabs.loadInBackground", true);

// set behavior of pages normally meant to open in a new window (such as target="_blank"// or from an external program), but that have instead been loaded in a new tab.// true: load the new tab in the background, leaving focus on the current tab// false: load the new tab in the foreground, taking the focus from the current tab.user_pref("browser.tabs.loadDivertedInBackground", false);

// 3022: hide recently bookmarked items (you still have the original bookmarks) (FF49+)user_pref("browser.bookmarks.showRecentlyBookmarked", false);

// 3023: disable automigrate, current default is false but may change (FF49+)// need more info, but lock down for nowuser_pref("browser.migrate.automigrate.enabled", false);

// END: internal custom pref to test for syntax errorsuser_pref("ghacks_user.js.parrot", "No no he's not dead, he's, he's restin'! Remarkable bird, the Norwegian Blue");

 9996: PALEMOON SPECIFIC ( https://www.palemoon.org/ )

// 9996-1: (v25.6+) disable canvas fingerprinting// user_pref("canvas.poisondata", true);

// 9996-2: (v25.2+) control HSTS// If editing this in about:config PM needs to be fully closed and then restarted// NOTE: This is a trade-off between privacy vs security. HSTS was designed to increase// security to stop MiTM attacks but can also be misused as a fingerprinting vector, by// scrapping previously visited sites. Recommended: security over privacy. Your choice.// user_pref("network.stricttransportsecurity.enabled", true);

// 9996-3: (v25.0+) controls whether to ignore an expired state of stapled OCSP responses// If set to true, breaks with RFC6066 (like Firefox) and ignores the fact that stapled// OCSP responses may be expired. If false (the default) aborts the connection.// user_pref("security.ssl.allow_unsafe_ocsp_response", false);

// 9996-4: (v25.6+) Controls whether to completely ignore "autocomplete=off" on login fields// user_pref("signon.ignoreAutocomplete", false);

// 9996-5: (v26.0+) read Moonchild's description on the palemoon forum thread linked above// user_pref("dom.disable_beforeunload", true);

 9997: DEPRECATED

// 2607: (23+) disable page thumbnails, it was around v23, not 100% sure when// this pref was replaced with browser.pagethumbnails.capturing_disabled// user_pref("pageThumbs.enabled", false);

// 2408: (31+) disable network API - fingerprinting vector// user_pref("dom.network.enabled", false);

// 2620: (35+) disable WebSockets// https://developer.mozilla.org/en-US/Firefox/Releases/35// user_pref("network.websocket.enabled", false);

// 2023: (37+) disable camera autofocus callback (was in 36, not in 37)// Not part of any specification, the API will be superceded by the WebRTC Capture// and Stream API ( http://w3c.github.io/mediacapture-main/getusermedia.html )// https://developer.mozilla.org/en-US/docs/Mozilla/Firefox_OS/API/CameraControl/// user_pref("camera.control.autofocus_moving_callback.enabled", false);

// 1804: (41+) disable plugin enumeration// user_pref("plugins.enumerable_names", "");

// 0420: (42+) disable tracking protection// this particular pref was never in stable// labelled v42+ because that's when tracking protection landed// user_pref("browser.polaris.enabled", false);

// 2803: (42+) what to clear on shutdown// https://bugzilla.mozilla.org/show_bug.cgi?id=1102184#c23// user_pref("privacy.clearOnShutdown.passwords", false);

// 0411: (43+) disable safebrowsing urls & download// user_pref("browser.safebrowsing.gethashURL", "");// user_pref("browser.safebrowsing.malware.reportURL", "");// user_pref("browser.safebrowsing.provider.google.appRepURL", "");// user_pref("browser.safebrowsing.reportErrorURL", "");// user_pref("browser.safebrowsing.reportGenericURL", "");// user_pref("browser.safebrowsing.reportMalwareErrorURL", "");// user_pref("browser.safebrowsing.reportMalwareURL", "");// user_pref("browser.safebrowsing.reportURL", "");// user_pref("browser.safebrowsing.updateURL", "");

// 0420: (43+) disable tracking protection. FF43+ URLs are now part of safebrowsing// https://wiki.mozilla.org/Security/Tracking_protection (look under Prefs)// NOTE: getupdateURL = WRONG / never existed. updateURL = CORRECT and has been added FYI// user_pref("browser.trackingprotection.gethashURL", "");// user_pref("browser.trackingprotection.getupdateURL", "");// user_pref("browser.trackingprotection.updateURL", "");

// 1803: (43+) remove plugin finder service// http://kb.mozillazine.org/Pfs.datasource.url// user_pref("pfs.datasource.url", "");

// 2403: (43+) disable scripts changing images - test link below// http://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_img_src2// WARNING: will break some sites such as Google Maps and a lot of web apps// user_pref("dom.disable_image_src_set", true);

// 2615: (43+) disable http2 for now as well// user_pref("network.http.spdy.enabled.http2draft", false);

// 3001a: (43+) disable warning when a domain requests full screen// replaced by setting full-screen-api.warning.timeout to zero// user_pref("full-screen-api.approval-required", false);

// 3003: (43+) disable new search panel UI [Classic Theme Restorer can restore the old search]// user_pref("browser.search.showOneOffButtons", false);

// 1201: (44+) block rc4 whitelist// https://developer.mozilla.org/en-US/Firefox/Releases/44#Security// user_pref("security.tls.insecure_fallback_hosts.use_static_list", false);

// 2417: (44+) disable SharedWorkers, which allow the exchange of data between iFrames that// are open in different tabs, even if the sites do not belong to the same domain.// https://www.torproject.org/projects/torbrowser/design/#identifier-linkability (no. 8)// https://bugs.torproject.org/15562// is used in FF 45and 46 code once, to set it for a test// user_pref("dom.workers.sharedWorkers.enabled", false);

// 1005: (45+) disable deferred level of storing extra session data 0=all 1=http-only 2=none// user_pref("browser.sessionstore.privacy_level_deferred", 2);

// 0334b: (46+) disable FHR (Firefox Health Report) v2 data being sent to Mozilla servers// user_pref("datareporting.policy.dataSubmissionEnabled.v2", false);

// 0373: (46+) disable "Pocket". FF46 replaced these with extensions.pocket.*// user_pref("browser.pocket.enabled", false);// user_pref("browser.pocket.api", "");// user_pref("browser.pocket.site", "");// user_pref("browser.pocket.oAuthConsumerKey", "");

// 0410e: (46+) safebrowsing// user_pref("browser.safebrowsing.appRepURL", ""); // Google application reputation check

// 0333b: (47+) disable about:healthreport page UNIFIED// user_pref("datareporting.healthreport.about.reportUrlUnified", "data:text/plain,");

// 0807: (47+) disable history manipulation// https://developer.mozilla.org/en-US/docs/Web/Guide/API/DOM/Manipulating_the_browser_history// WARNING: if set to false it breaks some sites (youtube) ability to correctly show the// url in location bar and for the forward/back tab history to work// user_pref("browser.history.allowPopState", false);// user_pref("browser.history.allowPushState", false);// user_pref("browser.history.allowReplaceState", false);

// 0806: (48+) disable 'unified complete': 'Search with [default search engine]'// this feature has been added back in Classic Theme Restorer// http://techdows.com/2016/05/firefox-unified-complete-aboutconfig-preference-removed.html// user_pref("browser.urlbar.unifiedcomplete", false);

// 3006: (48+) disable enforced add-on signing// NOTE: the preference is still in FF48+, but it's legacy code and does not work in stable// user_pref("xpinstall.signatures.required", false);

// 0372: (49+) disable "Hello" (TokBox/Telefonica WebRTC voice & video call PUP) WebRTC (IP leak)// https://www.mozilla.org/en-US/privacy/firefox-hello/// https://security.stackexchange.com/questions/94284/how-secure-is-firefox-hello// https://support.mozilla.org/en-US/kb/hello-status// user_pref("loop.enabled", false);// user_pref("loop.server", "");// user_pref("loop.feedback.formURL", "");// user_pref("loop.feedback.manualFormURL", "");// additional facebook loop settings// user_pref("loop.facebook.appId", "");// user_pref("loop.facebook.enabled", false);// user_pref("loop.facebook.fallbackUrl", "");// user_pref("loop.facebook.shareUrl", "");// https://groups.google.com/d/topic/mozilla.dev.platform/nyVkCx-_sFw/discussion// user_pref("loop.logDomains", false);

// 2202: (49+) ONE of the new window UI prefs// user_pref("dom.disable_window_open_feature.scrollbars", true);

// 2431: (49+) disable ONE of the push notification prefs// user_pref("dom.push.udp.wakeupEnabled", false);

// 0308: (50+) disable update plugin notifications// if using Flash/Java/Silverlight, it is best to turn on their own auto-update mechanisms.// See 1804 below: Mozilla only checks a few plugins and will soon do away with NPAPI// user_pref("plugins.update.notifyUser", false);

// 0410a: (50+) "Block dangerous and deceptive content" pref name change// user_pref("browser.safebrowsing.enabled", false); // FF49 and earlier

// 1202: (50+) disable rc4 ciphers// https://www.fxsitecompat.com/en-CA/docs/2016/rc4-support-has-been-completely-removed/// https://trac.torproject.org/projects/tor/ticket/17369// user_pref("security.ssl3.ecdhe_ecdsa_rc4_128_sha", false);// user_pref("security.ssl3.ecdhe_rsa_rc4_128_sha", false);// user_pref("security.ssl3.rsa_rc4_128_md5", false);// user_pref("security.ssl3.rsa_rc4_128_sha", false);

// 1809: (50+) remove Mozilla's plugin update URL// user_pref("plugins.update.url", "");

// 1851: (51+) delay play of videos until they're visible// https://bugzilla.mozilla.org/show_bug.cgi?id=1180563// user_pref("media.block-play-until-visible", true);

// 2504: (51+) disable virtual reality devices// user_pref("dom.vr.oculus050.enabled", false);

// 2614: (51+) disable SPDY// user_pref("network.http.spdy.enabled.v3-1", false);

9998: TO INVESTIGATE - TOR UPLIFT

// RESOLVED// 1400's: set whitelisted system fonts only (FF52+)// If whitelist is empty, then whitelisting is considered disabled and all fonts are allowed.// https://bugzilla.mozilla.org/show_bug.cgi?id=1121643// user_pref("font.system.whitelist", "");

// 2698-append: privacy.firstparty.isolate.restrict_opener_access// https://bugzilla.mozilla.org/show_bug.cgi?id=1319773

// ACTIVE// 1200's: Isolate the HSTS and HPKP cache by first party domain// https://bugzilla.mozilla.org/show_bug.cgi?id=1323644

// 2400's: reduce precision of time exposed by javascript// https://bugzilla.mozilla.org/show_bug.cgi?id=1217238// user_pref("javascript.options.privacy.reduce_time_precision", true);

// 2699-append: resource://URIs leak// https://trac.torproject.org/projects/tor/ticket/8725// https://bugzilla.mozilla.org/show_bug.cgi?id=863246// test: https://www.browserleaks.com/firefox

// ASSIGNED// 2001: preference to fully disable WebRTC JS API// https://bugzilla.mozilla.org/show_bug.cgi?id=1314443

// 2699-append: enable fingerprinting resistence to WebGL// https://bugzilla.mozilla.org/show_bug.cgi?id=1217290

// 2699-append: checkbox in about#preferences#privacy for privacy.resistFingerprinting// when this lands, add note to 2699// https://bugzilla.mozilla.org/show_bug.cgi?id=1308340

// 2699-append: use UTC timezone (spoof as UTC 0)// https://bugzilla.mozilla.org/show_bug.cgi?id=1330890

// 2699-append: new window sizes to round to hundreds// Note: override values, future may enforce a select set of (inner) window measurements// If override values are too big, the code falls back and determines it for you// https://bugzilla.mozilla.org/show_bug.cgi?id=1330882// user_pref("privacy.window.maxInnerWidth", 1366);// user_pref("privacy.window.maxInnerHeight", 768);

// BACKLOG// 1400's: prevent local font enumeration// https://bugzilla.mozilla.org/show_bug.cgi?id=732096

// 1800's: disable "This Plugin is Disabled" overlay// https://bugzilla.mozilla.org/show_bug.cgi?id=967979// user_pref("privacy.plugin_disabled_barrier.enabled", false);

// 2500's: disable/mitigate canvas fingerprinting// https://bugzilla.mozilla.org/show_bug.cgi?id=1041818

// 2500's: enable prompt (site permission) before allowing canvas data extraction// https://bugzilla.mozilla.org/show_bug.cgi?id=967895

// 2600's: window.name// https://bugzilla.mozilla.org/show_bug.cgi?id=444222

// 2698-append: checkbox in about:preferences#privacy for privacy.firstparty.isolate// when this lands, add note to 2611// https://bugzilla.mozilla.org/show_bug.cgi?id=1312655

// 2698-append: FPI and HTTP Alternative Services (see 2666)// https://bugzilla.mozilla.org/show_bug.cgi?id=1334690

// 2698-append: FPI and SPDY/HTTP2// https://bugzilla.mozilla.org/show_bug.cgi?id=1334693

// 2699-append: disable keyboard fingerprinting// Test: https://w3c.github.io/uievents/tools/key-event-viewer.html// https://bugzilla.mozilla.org/show_bug.cgi?id=1222285

// 2699-append: disable WebSpeech API// https://bugzilla.mozilla.org/show_bug.cgi?id=1333641// see also: web speech exposes TTS engines// https://bugzilla.mozilla.org/show_bug.cgi?id=1233846

// 2699-append: spoof Navigator API// https://bugzilla.mozilla.org/show_bug.cgi?id=1333651

// 2699-append: set and enforce various prefs with privacy.resistFingerprinting// https://bugzilla.mozilla.org/show_bug.cgi?id=1333933

// 2699-append: bundle and whitelist fonts with privacy.resistFingerprinting// https://bugzilla.mozilla.org/show_bug.cgi?id=1336208

9999: TO INVESTIGATE - OTHER

// 1600's: restrict the contents of referrers attached to cross-origin requests (FF52+)// 0- 1- 2-scheme+hostname+port// user_pref("network.http.referer.XOriginTrimmingPolicy", 2);

// 1600's: default referrer fallback override? (FF52+?)// 0-no-referer 1-same-origin 2-strict-origin-when-cross-origin// 3-no-referrer-when-downgrade (default)// https://bugzilla.mozilla.org/show_bug.cgi?id=1304623// user_pref("network.http.referer.userControlPolicy", 3);

// 3000's: show system add-ons in about:addons (so you can enable/disable them) - NOT landed yet// https://bugzilla.mozilla.org/show_bug.cgi?id=1231202// user_pref("extensions.hideSystemAddons", false); // (hidden pref)// ^^ keep an eye on extensions.systemAddon* prefs// dom.presentation.*// privacy.userContext.* (Containers)// use a private container for thumbnail loads (FF51+)// user_pref("privacy.usercontext.about_newtab_segregation.enabled", true);// browser.newtabpage.remote*// user_pref("browser.formfill.expire_days", 1);// user_pref("javascript.options.shared_memory", false);// user_pref("plugin.disable_full_page_plugin_for_types", "application/pdf");// network.http.enablePerElementReferrer// history.length XSHM fix// https://bugzilla.mozilla.org/show_bug.cgi?id=1315203// sandbox levels (recommended to leave at what Firefox sets it to)// https://www.ghacks.net/2017/01/23/how-to-change-firefoxs-sandbox-security-level/// security.sandbox.content.level

APPENDIX A: TEST SITES

01: Fingerprinting

02: Multiple Tests [single page]

03: Multiple Tests [multi-page]

04: Encryption / Ciphers / SSL/TLS / Certificates

05: Other

06: Safe Browsing, Tracking Protection

APPENDIX B: FIREFOX ADD-ONS

* Don't use both cookie add-ons** Yes, I use google search sometimes (my choice). I have some global add-ons that address     Âtracking in URLS, but am still looking for a working, comprehensible solution.*** It's not just Java! Covers JS, Cookies, Java, Flash... and more. Customisable controls and defaults

NOTE: At the time of publication the following are not e10s compatible: Google Privacy, NoRedirect, UAControl, User-Agent JS Fixer, Popup Blocker Ultimate

Now You: Please leave comments below suggesting new entries and changes. Feel free to add other information, such as compatibility, links to resources or suggestions on how to organize the list better.

ADVERTISEMENTSummaryArticle NameA comprehensive list of Firefox privacy and security settingsDescriptionA list of Firefox privacy and security preferences in a user.js file to modify the browser and harden it against privacy and security leaks.AuthorMartin BrinkmannPublisherGhacks Technology NewsLogoAdvertisement
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