Preferences

Mobile-Config-Firefox has custom preferences, which can be set via the about:mobile page (or alternatively in about:config).

Preference naming convention

  • Always uses mcf as the root branch name

  • Boolean preferences should always end with .enabled

  • Use camel case if there’s more than one word in one of the branch

Example:

mcf.toolbar.tabCounter.enabled

Default Preferences

browser.urlbar.suggest.topsites

  • Value: false

  • Description: …

  • Reason: Do not suggest facebook, ebay, reddit etc. in the urlbar. Same as Settings -> Privacy & Security -> Address Bar -> Shortcuts. As side-effect, the urlbar results are not immediatelly opened once clicking the urlbar.

browser.urlbar.suggest.engines

  • Value: false

  • Description: …

  • Reason: Do not suggest search engines. Even though amazon is removed via policies.json, it gets installed shortly after the browser is opened. With this option, at least there is no big “Search with Amazon” message in the urlbar results as soon as typing the letter “a”.

media.webrtc.camera.allow-pipewire

  • Value: true

  • Description: …

  • Reason: FF >= 116 allows to use cameras via Pipewire. While it will likely still take a while until this is made the default, on most mobile devices it makes a lot of sense to enable it unconditionally, as cameras usually only work with libcamera, not via plain v4l2.

dom.maxtouchpoints.testing.value

  • Value: 1

  • Description: …

  • Reason: Make navigator.maxTouchPoints return 1 for clients to determine this is a touch device. This is the same value used by Web Developer Tools > Responsive Design Mode > Enable touch simulation.

browser.urlbar.trimHttps

  • Value: true

  • Description: …

  • Reason: Hide https:// in urlbar by default to save space and make more relevant parts of the urlbar visible.

widget.use-xdg-desktop-portal.file-picker

  • Value: 1

  • Description: …

  • Reason: Use the xdg-desktop-portal.file-picker by default, e.g., for a native file-picker instead of gtk-file-picker on Plasma Mobile.

apz.allow_zooming

  • Value: true

  • Description: …

  • Reason: Enable android-style pinch-to-zoom

apz.allow_double_tap_zooming

  • Value: true

  • Description: …

  • Reason: Enable android-style pinch-to-zoom

defaultPref(‘dom.w3c_touch_events.legacy_apis.enabled

  • Value: true

  • Description: …

  • Reason: Enable legacy touch event APIs, as some websites use this to check for mobile compatibility and Firefox on Android behaves the same way.

browser.tabs.inTitlebar

  • Value: 1

  • Description: …

  • Reason: Save vertical space by hiding the titlebar.

browser.search.suggest.enabled

  • Value: false

  • Description: …

  • Reason: Disable search suggestions

browser.newtabpage.enabled

  • Value: false

  • Description: Show Firefox New Tab page as the homepage

  • Reason: Faster startup time and less distractions.

toolkit.legacyUserProfileCustomizations.stylesheets

  • Value: true

  • Description: …

  • Reason: Allow UI customizations with userChrome.css and userContent.css

browser.urlbar.clickSelectsAll

  • Value: true

  • Description: …

  • Reason: Select the entire URL with one click.

toolkit.cosmeticAnimations.enabled

  • Value: false

  • Description: …

  • Reason: Reduce CPU usage.

browser.download.animateNotifications

  • Value: false

  • Description: …

  • Reason: Reduce CPU usage.

browser.ai.control.default

  • Value: ‘blocked’

  • Description: Turn AI killswitch to off

  • Reason: Reduce CPU usage.

browser.ai.control.translations

  • Value: ‘available’

  • Description: Translation service

  • Reason: Keep translations feature despite the AI killswitch has been switched to off.