This article shows the difference between the default preferences of Firefox 147.0 beta 6 and Firefox 146.0.1. The diff table below is generated using my small script firefox-prefjs-surveyer.

Preference difference
PrefFirefox 147.0 beta 6Firefox 146.0.1
accessibility.anchorPositionedAsDetails.enabled undefined false
accessibility.windows.suppress-after-clipboard-copy 2 undefined
accessibility.windows.suppress-for-snap-layout 2 undefined
app.normandy.test-prefs.bool undefined false
app.normandy.test-prefs.integer undefined 0
app.normandy.test-prefs.string undefined
app.releaseNotesURL https://www.mozilla.org/%LOCALE%/firefox/%VERSION%/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-desktop&utm_campaign=whatsnew https://www.mozilla.org/%LOCALE%/firefox/%VERSION%beta/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-desktop&utm_campaign=whatsnew
app.releaseNotesURL.aboutDialog https://www.mozilla.org/%LOCALE%/firefox/%VERSION%/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-desktop&utm_campaign=about-dialog https://www.mozilla.org/%LOCALE%/firefox/%VERSION%beta/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-desktop&utm_campaign=about-dialog
app.update.channel release beta
app.update.url.details https://www.mozilla.org/%LOCALE%/firefox/notes https://www.mozilla.org/%LOCALE%/firefox/beta/notes
app.update.url.manual https://www.mozilla.org/%LOCALE%/firefox/new?reason=manual-update https://www.mozilla.org/%LOCALE%/firefox/beta?reason=manual-update
apz.android.chrome_fling_physics.friction 0.015 undefined
apz.android.chrome_fling_physics.inflexion 0.35 undefined
apz.android.chrome_fling_physics.stop_threshold 0.1 undefined
apz.async_scroll_css_anchor_pos undefined true
apz.mac.enable_double_tap_zoom_touchpad_gesture true undefined
apz.windows.check_for_pan_gesture_conversion true undefined
apz.windows.force_disable_direct_manipulation false undefined
apz.windows.use_direct_manipulation true undefined
browser.aiwindow.enabled undefined false
browser.contextual-services.contextId.rotation-in-days 7 3
browser.display.windows.non_native_menus 2 undefined
browser.ipProtection.optedOut undefined false
browser.ml.chat.shortcut.onboardingMouseoverCount undefined 0
browser.newtabpage.activity-stream.discoverystream.imageProxy.enabled undefined false
browser.newtabpage.activity-stream.discoverystream.sections.clientLayout.enabled undefined false
browser.newtabpage.activity-stream.discoverystream.spoc-topsites-positions 2 undefined
browser.newtabpage.activity-stream.discoverystream.spocTopsitesAdTypes undefined
browser.newtabpage.activity-stream.discoverystream.spocTopsitesPlacement.enabled true undefined
browser.newtabpage.activity-stream.discoverystream.spocTopsitesZoneIds undefined
browser.newtabpage.activity-stream.discoverystream.thumbsUpDown.region-thumbs-config US US, CA
browser.newtabpage.activity-stream.feeds.trendingsearchfeed true undefined
browser.newtabpage.activity-stream.sov.amp.allocation undefined 100, 100, 100
browser.newtabpage.activity-stream.sov.enabled undefined false
browser.newtabpage.activity-stream.sov.frecency.allocation undefined 0, 0, 0
browser.newtabpage.activity-stream.sov.frecency.exposure undefined false
browser.newtabpage.activity-stream.sov.name undefined SOV-20251122215625
browser.newtabpage.activity-stream.support.url https://support.mozilla.org/1/firefox/146.0.1/Linux/en-US/new-tab https://support.mozilla.org/1/firefox/147.0/Linux/en-US/new-tab
browser.newtabpage.activity-stream.system.trendingSearch.enabled false undefined
browser.newtabpage.activity-stream.telemetry.ut.events false true
browser.newtabpage.activity-stream.trendingSearch.defaultSearchEngine Google undefined
browser.newtabpage.activity-stream.trendingSearch.enabled true undefined
browser.newtabpage.activity-stream.trendingSearch.variant undefined
browser.newtabpage.activity-stream.widgets.enabled undefined false
browser.newtabpage.activity-stream.widgets.maximized undefined false
browser.newtabpage.activity-stream.widgets.system.maximized undefined false
browser.safebrowsing.provider.google5.enabled false true
browser.safebrowsing.provider.mozilla.lists base-track-digest256,mozstd-trackwhite-digest256,google-trackwhite-digest256,content-track-digest256,mozplugin-block-digest256,mozplugin2-block-digest256,ads-track-digest256,social-track-digest256,analytics-track-digest256,base-fingerprinting-track-digest256,content-fingerprinting-track-digest256,base-cryptomining-track-digest256,content-cryptomining-track-digest256,fanboyannoyance-ads-digest256,fanboysocial-ads-digest256,easylist-ads-digest256,easyprivacy-ads-digest256,adguard-ads-digest256,social-tracking-protection-digest256,social-tracking-protection-facebook-digest256,social-tracking-protection-linkedin-digest256,social-tracking-protection-twitter-digest256,base-email-track-digest256,content-email-track-digest256,consent-manager-track-digest256,anti-fraud-track-digest256 base-track-digest256,mozstd-trackwhite-digest256,google-trackwhite-digest256,content-track-digest256,mozplugin-block-digest256,mozplugin2-block-digest256,ads-track-digest256,social-track-digest256,analytics-track-digest256,base-fingerprinting-track-digest256,content-fingerprinting-track-digest256,base-cryptomining-track-digest256,content-cryptomining-track-digest256,fanboyannoyance-ads-digest256,fanboysocial-ads-digest256,easylist-ads-digest256,easyprivacy-ads-digest256,adguard-ads-digest256,social-tracking-protection-digest256,social-tracking-protection-facebook-digest256,social-tracking-protection-linkedin-digest256,social-tracking-protection-twitter-digest256,base-email-track-digest256,content-email-track-digest256,consent-manager-track-digest256,anti-fraud-track-digest256,harmfuladdon-block-digest256,harmfuladdon-entitylist-digest256
browser.search.suggest.ohttp.enabled true undefined
browser.search.suggest.ohttp.featureGate false undefined
browser.sessionstore.log.appender.file.logOnSuccess false true
browser.sessionstore.loglevel Warn Debug
browser.tabs.documentchannel.parent-controlled false undefined
browser.tabs.dragDrop.multiselectStacking false true
browser.topsites.contile.sov.enabled true undefined
browser.translations.quickAction.enabled undefined false
browser.urlbar.quicksuggest.dataCollection.enabled false undefined
dap.ohttp.hpke undefined https://dap-09-3.api.divviup.org/ohttp-configs
dap.ohttp.relayURL undefined https://mozilla-ohttp-dap.mozilla.fastly-edge.com/
devtools.jsonview.size-profiler.enabled undefined false
dom.about-blank-ckeditor-hack.disabled-domains undefined
dom.about-blank-ckeditor-hack.enabled undefined false
dom.event.keypress.key.allow_lone_surrogate true false
dom.events.asyncClipboard.clipboardItem true undefined
dom.events.asyncClipboard.readText true undefined
dom.input.showPicker_datalist.enabled false true
dom.jsipc.send_typed undefined false
dom.keyboardevent.dispatch_during_composition true undefined
dom.navigation.api.internal_method_tracker undefined false
dom.navigation.webidl.enabled false true
dom.quotaManager.temporaryStorage.clearNonPersistedZeroUsageOrigins undefined false
dom.quotaManager.temporaryStorage.initialOriginAccessTimeOffsetSec undefined 0
dom.quotaManager.temporaryStorage.maxOriginsToClearDuringCleanup undefined 150
dom.security.sanitizer.enabled false true
dom.security.trusted_types.enabled false true
dom.security.unexpected_system_load_telemetry_enabled false true
dom.selection.exclude_non_selectable_nodes undefined false
dom.storage_access.headers.enabled false true
dom.text_fragments.create_text_fragment.enabled true undefined
dom.webgpu.enabled false true
dom.webgpu.service-workers.enabled false true
dom.webnotifications.icon_encoding_utf8.enabled true undefined
dom.workers.throttling.enabled false true
extensions.cookie.rejectWhenInvalid true undefined
extensions.webcompat-reporter.enabled false true
extensions.webextensions.base-content-security-policy.v3-with-localhost undefined script-src 'self' 'wasm-unsafe-eval' http://localhost:* http://127.0.0.1:*;
first-startup.category-tasks-enabled undefined true
gfx.android.rgb16.force false undefined
gfx.canvas.accelerated.max-data-shmems undefined 400
gfx.canvas.remote.use-draw-image-fast-path-d3d true undefined
gfx.compositor.gpu-migration 1 undefined
gfx.core-animation.tint-opaque false undefined
gfx.direct3d11.allow-keyed-mutex true undefined
gfx.direct3d11.break-on-error false undefined
gfx.direct3d11.enable-debug-layer false undefined
gfx.direct3d11.reuse-decoder-device true undefined
gfx.direct3d11.reuse-decoder-device-force-enabled false undefined
gfx.direct3d11.sleep-on-create-device 0 undefined
gfx.direct3d11.use-double-buffering false undefined
gfx.use-iosurface-textures false undefined
gfx.use-mutex-on-present false undefined
gfx.use-surfacetexture-textures false undefined
gfx.webrender.precise-conic-gradients-swgl false true
gfx.webrender.precise-radial-gradients-swgl false true
gfx.webrender.software.d3d11 true undefined
gfx.webrender.software.d3d11.upload-mode 4 undefined
gl.allow-high-power true undefined
gl.ignore-dx-interop2-blacklist false undefined
identity.fxaccounts.migrateToDevEdition false undefined
identity.fxaccounts.oauth.enabled true undefined
image.avif.enabled true undefined
intl.hyphenation-alias.kmr-* kmr undefined
intl.hyphenation-alias.ku-* undefined ku
javascript.options.experimental.iterator_sequencing undefined true
javascript.options.inlining_bytecode_max_length 130 140
javascript.options.use_js_microtask_queue false true
layers.d3d11.enable-blacklist true undefined
layers.d3d11.force-warp false undefined
layers.iosurfaceimage.recycle-limit 15 undefined
layout.abspos.fragmentainer-aware-positioning.enabled undefined false
layout.css.anchor-positioning.enabled false true
layout.css.anchor-positioning.position-try-order.enabled undefined false
layout.css.attr.enabled undefined false
layout.css.grid-multi-pass-track-sizing.enabled true undefined
layout.css.letter-spacing.model 0 2
layout.css.module-scripts.enabled false true
layout.css.scroll-behavior.damping-ratio 1.0 undefined
layout.css.scroll-behavior.same-physics-as-user-input undefined false
layout.css.scroll-behavior.spring-constant 250.0 undefined
layout.css.scroll-snap.damping-ratio undefined 1.0
layout.css.scroll-snap.spring-constant undefined 250.0
layout.dynamic-reflow-roots.enabled false true
mathml.legacy_mathvariant_attribute.disabled false true
mathml.mathspace_names.disabled false true
mathml.operator_dictionary_accent.disabled undefined false
media.video-queue.hw-accel-size undefined 3
media.webrtc.simulcast.vp9.enabled false true
memory.phc.size_kb 1152 16384
network.auth.confirmAuth.enabled false undefined
network.auth.use_redirect_for_retries false true
network.buffer.default_size undefined 65536
network.dns.native_https_timeout_android 20000 undefined
network.dns.native_https_timeout_mac_msec 5000 undefined
network.http.dictionaries.enable false true
network.http.http3.fallback_to_h2_on_error undefined true
network.http.http3.pmtud undefined false
network.http.http3.retry_different_ip_family false true
network.http.rcwn.enabled true false
network.http.rcwn.race_with_non_ssd undefined true
network.http.retry_with_another_half_open false true
network.jar.record_failure_reason false true
network.trr.async_connInfo false true
network.trr.idle_timeout_for_http3_conn 30 400
network.trr.retry_on_recoverable_errors true false
network.trr_ui.fallback_was_checked undefined true
places.frecency.pages.halfLifeDays undefined 30
places.frecency.pages.highWeight undefined 100
places.frecency.pages.interactions.manyKeypresses undefined 50
places.frecency.pages.interactions.maxVisitGapSeconds undefined 120
places.frecency.pages.interactions.viewTimeIfManyKeypressesSeconds undefined 20
places.frecency.pages.interactions.viewTimeSeconds undefined 60
places.frecency.pages.lowWeight undefined 20
places.frecency.pages.mediumWeight undefined 50
places.frecency.pages.numSampledVisits undefined 10
places.frecency.pages.veryHighWeight undefined 200
places.semanticHistory.featureGate false true
places.semanticHistory.supportedRegions undefined [["AU",["en-*"]],["CA",["en-*"]],["GB",["en-*"]],["IE",["en-*"]],["NZ",["en-*"]],["PH",["en-*"]],["US",["en-*"]]]
privacy.trackingprotection.harmfuladdon.enabled undefined true
prompts.modalType.confirmAuth 2 undefined
security.disallow_non_local_systemprincipal_in_tests undefined false
security.ssl3.ecdhe_ecdsa_aes_128_sha true false
security.ssl3.ecdhe_ecdsa_aes_256_sha true false
security.webauthn.allow_with_certificate_override undefined false
security.webauthn.enable_macos_passkeys true undefined
services.sync.engine.bookmarks.validation.enabled undefined true
services.sync.engine.passwords.validation.enabled undefined true
services.sync.prefs.sync.privacy.trackingprotection.harmfuladdon.enabled undefined true
toolkit.telemetry.enabled false true
ui.new-webcompat-reporter.send-more-info-link false true
urlclassifier.features.harmfuladdon.blocklistTables undefined harmfuladdon-block-digest256
urlclassifier.features.harmfuladdon.entitylistTables undefined harmfuladdon-entitylist-digest256
webgl.dxgl.enabled false undefined
webgl.dxgl.needs-finish false undefined
webgl.prefer-16bpp false undefined
widget.android.use-surfacecontrol false undefined
widget.support-xdg-config undefined true
widget.window-transforms.disabled false undefined