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.

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.

Loading the list

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.

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.

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

* "My mother was a tailor, she sewed my new blue pants"

* FF version: 51 (DESKTOP)

* authors: FLOTUS: Pants

VICE PRESIDENT: earthling (birth certificate on request)

SECRETARY: Martin Brinkmann

SPEAKER: Tom Hawack

CABINET: Just me, Conker, Rockin' Jerry, Ainatar, Parker Lewis

* url: https://www.ghacks.net/2015/08/18/a-comprehensive-list-of-firefox-privacy-and-security-settings/

* 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 copy prefs.js, rename it (eg to prefs.js.backup). That way, if you have problems, to restore FF to the state it was in beforehand, close FF, delete the prefs.js, rename your backup copy of prefs back to prefs.js, RENAME the user.js so it doesn't overwrite everything again, then start 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) It is more like a list of settings that generally differ from their defaults, and is aimed at improving security and privacy, at making a "quieter" FF, and at reducing fingerprinting and tracking; 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 for "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 because

the author prefers anonymity, security, and privacy over functionality [eg being able to

paste in Facebook, downloadable fonts, and other minor inconveniences]. You have been warned.

0202 & 0204 & 0207 & 0208: search, language and locale settings

0903 & 0904: master password (author set his up to last 5 minutes, default is once per session)

1007 & 1008: disabling/reducing session store saves affects recently closed tabs history

1204: security.ssl.require_safe_negotiation

1206: security.OCSP.require

1208: security.cert_pinning.enforcement_level

1209: TLS min and max

1210: disable 1024-DH Encryption

1211: disable SHA-1

1212: disable SSL session tracking

1401 & 1406: browser.display.use_document_fonts [author blocked fonts]

1404: default fonts [author changed default fonts]

1805: plugin.scan.plid.all [author blocked all plugins]

1807: disable auto-play of HTML5 media (may break some sites' playback)

2025: enable/disable media types [author's settings, choose your own]

2201: dom.event.contextmenu.enabled

2300's: workers/service.workers/push notifications etc may affect twitter, street view and other sites

2402: dom.event.clipboardevents.enabled

2404: dom.indexedDB.enabled [author killed indexedDB]

2415b: limit popup events

2421: two JS preferences that cause the odd issue (commented out, not worth the performance loss)

2507: keyboard fingerprinting (android + physical keyboard)

2508: hardware acceleration (performance vs lots of video, also fonts render differently)

[author killed hardware acceleration]

2509: dom.w3c_touch_events.enabled (you will want to change this if you use touch)

2619: network.http.redirection-limit

2627: various User Agent and navigator objects

2662: browser.download.forbid_open_with

2698: privacy.firstparty.isolate

2705: dom.storage.enabled

THANKS:

Special thanks to Martin Brinkmann and the ghacks community

Lots of websites, lots of people, too many to list but here are some excellent resources

https://github.com/pyllyukko/user.js

https://www.wilderssecurity.com/threads/firefox-lockdown.368003/

http://12bytes.org/articles/tech/firefoxgecko-configuration-guide-for-privacy-and-performance-buffs

https://www.privacy-handbuch.de/handbuch_21.htm (German)

******/

// 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_canary

user_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 check

user_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 browsing

user_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/16254

user_pref("browser.search.countryCode", "US"); // (hidden pref)

user_pref("browser.search.region", "US"); // (hidden pref)

// 0203: disable using OS locale, force APP locale

user_pref("intl.locale.matchOS", false);

// 0204: set APP local

user_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 locales

user_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 English

user_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=867501

user_pref("javascript.use_us_english_locale", true); // (hidden pref)

0300: QUIET FOX [PART 1]

No auto-phoning home for anything. You can still do manual updates. It is still important to do updates for security reasons. If you don't auto update, make sure you do manually. There are many legitimate reasons to turn off AUTO updates, including hijacked monetized extensions, time constraints, legacy issues, and fear of breakage/bugs

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 updates

user_pref("app.update.service.enabled", false);

// ensure update information is not suppressed

user_pref("app.update.silent", false);

// disable background update staging

user_pref("app.update.staging.enabled", false);

// 0302: disable browser auto installing update when you do a manual check

user_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 versions

user_pref("extensions.update.enabled", false);

// 0305: disable add-ons auto update

user_pref("extensions.update.autoUpdateDefault", false);

// 0306: disable add-on metadata updating

// sends daily pings to Mozilla about extensions and recent startups

user_pref("extensions.getAddons.cache.enabled", false);

// 0307: disable auto updating of personas (themes)

user_pref("lightweightThemes.update.enabled", false);

// 0309: disable sending Flash crash reports

user_pref("dom.ipc.plugins.flash.subprocess.crashreporter.enabled", false);

// 0310: disable sending the URL of the website where a plugin crashed

user_pref("dom.ipc.plugins.reportCrashURL", false);

// 0320: disable extension discovery

// featured extensions for displaying in Get Add-ons panel

user_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 false

user_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 enabled

user_pref("toolkit.telemetry.unifiedIsOptIn", true); // (hidden pref)

// 0331: remove url of server telemetry pings are sent to

user_pref("toolkit.telemetry.server", "");

// 0332: disable archiving pings locally - irrelevant if toolkit.telemetry.unified is false

user_pref("toolkit.telemetry.archive.enabled", false);

// 0333a: disable health report

user_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 default

user_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=1195552

user_pref("datareporting.policy.dataSubmissionEnabled", false);

// 0335: remove a telemetry clientID

// if you haven't got one, be proactive and set it now for future proofing

user_pref("toolkit.telemetry.cachedClientID", "");

// 0336: disable "Heartbeat" (Mozilla user rating telemetry)

// https://trac.torproject.org/projects/tor/ticket/18738

user_pref("browser.selfsupport.enabled", false); // (hidden pref)

user_pref("browser.selfsupport.url", "");

// 0340: disable experiments

// https://wiki.mozilla.org/Telemetry/Experiments

user_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 tests

user_pref("network.allow-experiments", false);

// 0350: disable crash reports

user_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 junk

user_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 attacks

user_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_API

user_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 sync

user_pref("services.sync.enabled", false); // (hidden pref)

0400: QUIET FOX [PART 2]

This section has security & tracking protection implications vs privacy concerns. These settings are geared up to make FF "quiet" & private. I am NOT advocating no protection. If you turn these off, then by all means please use something superior, such as uBlock Origin. IMPORTANT: This entire section is rather contentious. Safebrowsing is designed to protect users from malicious sites. Tracking protection is designed to lessen the impact of third parties on websites to reduce tracking and to speed up your browsing experience. These are both very good features provided by Mozilla. They do rely on third parties: Google for safebrowsing and Disconnect for tracking protection (someone has to provide the information). Additionally, SSL Error Reporting helps makes the internet more secure for everyone. If you do not understand the ramifications of disabling all of these, then it is advised that you enable them by commenting out the preferences and saving the changes, and then in about:config find each entry and right-click and reset the preference's value.

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/16931

user_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 updating

user_pref("services.blocklist.update_enabled", true);

user_pref("services.blocklist.signing.enforced", true);

user_pref("services.blocklist.onecrl.collection", "certificates"); // Revoked certificates

user_pref("services.blocklist.addons.collection", "addons");

user_pref("services.blocklist.plugins.collection", ""); // I have no plugins

user_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 engineering

user_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, updates

user_pref("browser.safebrowsing.provider.google.updateURL", ""); // update google lists

user_pref("browser.safebrowsing.provider.google.gethashURL", ""); // list hash check

user_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 conflicts

user_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 URLs

user_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-firefox

user_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 Protection

user_pref("privacy.trackingprotection.ui.enabled", true);

// 0430: disable SSL Error Reporting - PRIVACY

// https://gecko.readthedocs.org/en/latest/browser/base/sslerrorreport/preferences.html

user_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=1237198

user_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_FAQ

user_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_prefetching

user_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/Necko

user_pref("network.predictor.enabled", false);

// 0603a: disable more Necko/Captive Portal

// https://en.wikipedia.org/wiki/Captive_portal

// https://wiki.mozilla.org/Necko/CaptivePortal

user_pref("captivedetect.canonicalURL", "");

user_pref("network.captive-portal-service.enabled", false); // (FF52+?)

// 0604: disable search suggestions

user_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-links

user_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_host

user_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

Not ALL of these are strictly needed, some are for the truly paranoid, but included for a more comprehensive list (see comments on each one)

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 instead

user_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 SECURITY

user_pref("browser.urlbar.trimURLs", false);

// 0805: disable URLbar autofill - PRIVACY (shoulder surfers, forensics/unattended browser)

// http://kb.mozillazine.org/Inline_autocomplete

user_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);

// 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 practical

user_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_selector

user_pref("layout.css.visited_links_enabled", false);

// 0811: disable displaying javascript in history URLs - SECURITY

user_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 engine

user_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 preview

user_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 settings

user_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 30

user_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 entered

user_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=1217156

user_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:password@foo into ~http://user:password@(prefix)foo(suffix)

// but instead ~http://user@(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 cache

user_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_ssl

user_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 cache

user_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 data

user_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/13575

user_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 crash

user_pref("browser.sessionstore.resume_from_crash", false);

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

Note that your cipher and other settings can be used server side as a fingerprint attack vector: see https://www.securityartwork.es/2017/02/02/tls-client-fingerprinting-with-bro/ . You can either strengthen your encryption/cipher suite and protocols (security) or keep them at default and let Mozilla handle them (dragging their feet for fear of breaking legacy sites)

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:Renegotiation

user_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.signing

user_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 =1

user_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 DHE

user_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-256509998

user_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=967977

user_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.html

user_pref("security.ssl3.rsa_des_ede3_sha", false);

// 1214: disable 128 bits

user_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 root

user_pref("security.family_safety.mode", 0);

// 1216: disable insecure active content on https pages - mixed content

user_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

// time out, requests may not be handled well by servers, possible fingerprinting

// https://bugzilla.mozilla.org/show_bug.cgi?id=1246540#c145

user_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 this

user_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 you

user_pref("font.name.serif.x-unicode", "Georgia");

user_pref("font.name.serif.x-western", "Georgia"); // default Times New Roman

user_pref("font.name.sans-serif.x-unicode", "Arial");

user_pref("font.name.sans-serif.x-western", "Arial"); // default Arial

user_pref("font.name.monospace.x-unicode", "Lucida Console");

user_pref("font.name.monospace.x-western", "Lucida Console"); // default Courier New

// 1405: disable woff2

user_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_offset

user_pref("font.blacklist.underline_offset", "");

// 1408: disable graphite which FF49 turned back on by default

// In the past it had security issues - need citation

user_pref("gfx.font_rendering.graphite.enabled", false);

1600: HEADERS / REFERERS

Except for 1601 and 1602, these can all be best handled by an extension to block/spoof all and then whitelist if needed, otherwise too much of the internet breaks. Improve online privacy by controlling referrer information 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=1308725

user_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 minutes

user_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 XPConnect

user_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 allowed

user_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-toggle

user_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/GeckoMediaPlugins

user_pref("media.gmp-provider.enabled", false);

user_pref("media.gmp.trial-create.enabled", false);

// 1825: disable widevine CDM

user_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 Content

user_pref("browser.eme.ui.enabled", false); // hides "Play DRM Content" checkbox, restart required

user_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 server

user_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/16285

user_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/#webrtc

user_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 WebRTC

user_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/Privacy

user_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-concern

user_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_info

user_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 recognition

user_pref("media.webspeech.recognition.enable", false);

user_pref("media.webspeech.synth.enabled", false);

// 2022: disable screensharing

user_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 stuff

user_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 own

user_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/captureStream

user_pref("canvas.capturestream.enabled", false);

// 2027: disable camera image capture

// https://trac.torproject.org/projects/tor/ticket/16339

user_pref("dom.imagecapture.enabled", false);

// 2028: disable offscreen canvas

// https://developer.mozilla.org/en-US/docs/Web/API/OffscreenCanvas

user_pref("gfx.offscreencanvas.enabled", false);

UI MEDDLING

see http://kb.mozillazine.org/Prevent_websites_from_disabling_new_window_features

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 windows

user_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 meddling

user_pref("dom.disable_window_flip", true); // window z-order

user_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 toolbar

user_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 workers

user_pref("dom.workers.enabled", false);

user_pref("dom.serviceWorkers.enabled", false);

// 2302: disable service workers cache and cache storage

user_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 Twitter

user_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 Twitter

user_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 clipboard

user_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=1170911

user_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/WebTelephony

user_pref("dom.telephony.enabled", false);

// 2410: disable User Timing API

// https://trac.torproject.org/projects/tor/ticket/16336

user_pref("dom.enable_user_timing", false);

// 2411: disable resource/navigation timing

user_pref("dom.enable_resource_timing", false);

// 2412: disable timing attacks - javascript performance fingerprinting

// https://wiki.mozilla.org/Security/Reviews/Firefox/NavigationTimingAPI

user_pref("dom.enable_performance", false);

// 2414: disable shaking the screen

user_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_events

user_pref("dom.popup_allowed_events", "click dblclick");

// 2416: disable idle observation

user_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=ask

user_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-2015-2712

user_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=959985

user_pref("offline-apps.allow_by_default", false);

// Options>Advanced>Network>Tell me when a website asks to store data for offline use

user_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/13023

user_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=1313580

user_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=960426

user_pref("dom.netinfo.enabled", false);

// 2504: disable virtual reality devices

// https://developer.mozilla.org/en-US/docs/Web/API/WebVR_API

user_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/enumerateDevices

user_pref("media.navigator.enabled", false);

// 2506: disable video statistics - JS performance fingerprinting

/ https://trac.torproject.org/projects/tor/ticket/15757

user_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.htm

user_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 performance

user_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 default

user_pref("dom.w3c_touch_events.enabled", 0);

// 2510: disable Web Audio API (FF51+)

// https://bugzilla.mozilla.org/show_bug.cgi?id=1288359

user_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/ondevicechange

user_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.sendBeacon

user_pref("beacon.enabled", false);

// 2602: CIS 2.3.2 disable downloading on desktop

user_pref("browser.download.folderList", 2);

// 2603: always ask the user where to download - enforce user interaction for security

user_pref("browser.download.useDownloadDir", false);

// 2604: https://bugzil.la/238789#c19

user_pref("browser.helperApps.deleteTempFileOnExit", true);

// 2605: don't integrate activity into windows recent documents

user_pref("browser.download.manager.addToRecentDocs", false);

// 2606: disable hiding mime types (Options>Applications) not associated with a plugin

user_pref("browser.download.hide_plugins_without_extensions", false);

// 2607: disable page thumbnail collection

// look in profile/thumbnails directory - you may want to clean that out

user_pref("browser.pagethumbnails.capturing_disabled", true); // (hidden pref)

// 2608: disable JAR from opening Unsafe File Types

user_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/16222

user_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/16222

user_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/15758

user_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 well

user_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 convenience

user_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 20

user_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.contentLoadURL

user_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_policy

user_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_Integrity

user_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=1228457

user_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_reference

user_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

// http://browserspy.dk/showprop.php (for buildID)

// http://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=583181

user_pref("general.buildID.override", "20100101"); // (hidden pref)

// C: navigator.appName

user_pref("general.appname.override", "Netscape"); // (hidden pref)

// D: navigator.appVersion

user_pref("general.appversion.override", "5.0 (Windows)"); // (hidden pref)

// E: navigator.platform leaks in JS

user_pref("general.platform.override", "Win32"); // (hidden pref)

// F: navigator.oscpu

user_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 it

user_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=1215235

user_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 true

user_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=1281959

user_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.php

user_pref("mathml.disabled", true);

// 2664: disable DeviceStorage API

// https://wiki.mozilla.org/WebAPI/DeviceStorageAPI

user_pref("device.storage.enabled", false);

// 2665: sanitize webchannel whitelist

user_pref("webchannel.allowObject.urlWhitelist", "");

// 2666: disable HTTP Alternative Services

// https://www.ghacks.net/2015/08/18/a-comprehensive-list-of-firefox-privacy-and-security-settings/#comment-3970881

user_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-246468676

user_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/DYjAM

user_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=1255474

user_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=1288361

user_pref("security.block_script_with_wrong_mime", true);

// 2671: disable SVG (FF53+)

// https://bugzilla.mozilla.org/show_bug.cgi?id=1216893

user_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

This preference will be used as a generic switch for a wide range of items.

This section will attempt to list all the ramifications and Mozilla tickets

// 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=1281963

user_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 cookie

user_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.sessionOnly

user_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 <they expire/I close Firefox>

// 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_API

user_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=1213990

user_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 closes

user_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 own

user_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 logins

user_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-Del

user_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=today

user_pref("privacy.sanitize.timeSpan", 0);

3000: PERSONAL SETTINGS

Settings that are handy to migrate and/or are not in the Options interface. Users can put their own non-security/privacy/fingerprinting/tracking stuff here

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

// 3001: disable annoying warnings

user_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 tab

user_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 window

user_pref("browser.link.open_newwindow", 3);

// 3008: disable "Do you really want to leave this site?" popups

// https://support.mozilla.org/en-US/questions/1043508

user_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 previews

user_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 controls

user_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_events

user_pref("network.manage-offline-status", false);

// 3015: disable tab animation, speed things up a little

user_pref("browser.tabs.animate", false);

// 3016: disable fullscreeen animation. Test using F11.

// Animation is smother but is annoyingly slow, while no animation can be startling

user_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 out

user_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 right

user_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 = true

user_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 now

user_pref("browser.migrate.automigrate.enabled", false);

// END: internal custom pref to test for syntax errors

user_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/ )

Full list maintained by Moonchild: https://forum.palemoon.org/viewtopic.php?f=24&t=3357

If you have issues or questions about any of these, please use the palemoon forums

NOTE: This section is no longer maintained [after version 10]

// 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

Personally confirmed by resetting as well as via documentation and DXR searches.

NOTE: numbers may get re-used

// 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

https://wiki.mozilla.org/Security/Tor_Uplift/Tracking

// 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-ap