Current Version plugins

Firefox 55: new preferences and Ghacks user.js changes

This guide offers information on changes made to the Firefox 55 preferences, as well as new, deprecated, or removed Ghacks user.js preferences.

Mozilla released Firefox 55.0 to the Release channel on August 16, 2017. The new version of Firefox improved session restore on startup significantly, but is also incompatible with older versions as profile data changed.

Note: The Ghacks user.js file is a large well maintained file that lists Firefox preferences and values that are considered safer or better for privacy. You can check it out on the official project site. If you never worked with a user.js file before in Firefox, make sure you read the excellent overview to understand how it works.

Thanks goes to Earthling, Pants and anyone else who contributed to the list this month.

Firefox 55: new preferences and Ghacks user.js changes

firefox 55 prefs changes

Note: You may access the full Firefox 54 to 55 diff here. This is important information for users who already use the user.js file as it highlights new, removed, and changed preferences. It is recommended that you go through the listing and add the preferences to your current one that you require.

In total, there were 432 recorded diffs between Firefox 55.0 and Firefox 54.0. 207 of those are new, 66 removed, and 159 different.

Key points:

  • The list has a new section: 500 System Add-ons / Experiments. All system add-ons but Screenshots are disabled.
  • First Party Isolation is enabled.
  • OCSP servers are set to hard fail when the server does not respond.
  • Disabled TLS 1.0 and TLS 1.1

New preferences in Ghacks user.js for Firefox 55:

  • user_pref(“browser.onboarding.enabled”, false);
  • user_pref(“browser.tabs.remote.allowLinkedWebInFileUriProcess”, false);
  • user_pref(“browser.urlbar.speculativeConnect.enabled”, false);
  • user_pref(“extensions.formautofill.addresses.enabled”, false);
  • user_pref(“extensions.formautofill.experimental”, false);
  • user_pref(“extensions.formautofill.heuristics.enabled”, false);
  • user_pref(“extensions.shield-recipe-client.api_url”, “”);
  • user_pref(“extensions.shield-recipe-client.enabled”, false);
  • user_pref(“extensions.webcompat-reporter.enabled”, false);
  • user_pref(“media.eme.chromium-api.enabled”, false);
  • user_pref(“media.gmp-manager.updateEnabled”, false);
  • user_pref(“media.gmp-manager.url.override”, “data:text/plain,”);
  • user_pref(“network.auth.subresource-img-cross-origin-http-auth-allow”, false);
  • user_pref(“security.tls.enable_0rtt_data”, false);
  • user_pref(“toolkit.telemetry.newProfilePing.enabled”, false);
  • user_pref(“toolkit.telemetry.shutdownPingSender.enabled”, false);

New preferences that are commented out by default:

  • //user_pref(“browser.cache.memory.capacity”, 0);
  • //user_pref(“dom.ipc.processCount.file”, 1);
  • //user_pref(“extensions.screenshots.disabled”, true);
  • //user_pref(“extensions.systemAddon.update.url”, “”);
  • //user_pref(“media.wmf.vp9.enabled”, false);
  • //user_pref(“privacy.trackingprotection.annotate_channels”, false);
  • //user_pref(“privacy.trackingprotection.lower_network_priority”, false);
  • //user_pref(“toolkit.cosmeticAnimations.enabled”, false);

Newly activated preferences that were commented out previously:

  • user_pref(“browser.formfill.enable”, false);
  • user_pref(“browser.tabs.remote.separateFileUriProcess”, true);
  • user_pref(“privacy.firstparty.isolate”, true);
  • user_pref(“privacy.firstparty.isolate.restrict_opener_access”, true);
  • user_pref(“security.OCSP.require”, true);
  • user_pref(“security.tls.version.min”, 3); // previously inactive with value 2

Commented out preferences:

  • //user_pref(“privacy.trackingprotection.enabled”, true);
  • //user_pref(“privacy.trackingprotection.pbmode.enabled”, true);

Changed values of active preferences:

  • user_pref(“geo.wifi.uri”, “”); // 54alpha: “”
  • //user_pref(“privacy.window.maxInnerHeight”, 900); // 54alpha: 768
  • //user_pref(“privacy.window.maxInnerWidth”, 1600); // 54alpha: 1366

Removed from user.js:

  • user_pref(“dom.keyboardevent.dispatch_during_composition”, false); // default is false anyway
  • user_pref(“dom.vr.oculus.enabled”, false); // covered by dom.vr.enabled
  • user_pref(“dom.vr.openvr.enabled”, false); // covered by dom.vr.enabled
  • user_pref(“dom.vr.osvr.enabled”, false); // covered by dom.vr.enabled
  • user_pref(“extensions.pocket.api”, “”); // covered by extensions.pocket.enabled
  • user_pref(“extensions.pocket.oAuthConsumerKey”, “”); // covered by extensions.pocket.enabled
  • user_pref(“”, “”); // covered by extensions.pocket.enabled
  • //user_pref(“layers.async-pan-zoom.enabled”, true); // default is true already


  • browser.formautofill.enabled
  • browser.formfill.saveHttpsForms
  • browser.fullscreen.animate
  • browser.selfsupport.enabled
  • browser.selfsupport.url
  • browser.tabs.animate
  • dom.enable_user_timing
  • dom.keyboardevent.code.enabled

If you have questions about any of those preferences, remarks, or a comment, feel free to leave a comment below or head over to the project on GitHub to leave comments there.

Ghacks needs you. You can find out how to support us here or support the site directly by becoming a Patreon. Thank you for being a Ghacks reader.

The post Firefox 55: new preferences and Ghacks user.js changes appeared first on gHacks Technology News.

Leave a Comment

Your email address will not be published. Required fields are marked *

Menu Title