This is difference between the default preference of Firefox 141.0 and one of 140.0.4. This diff table is generated with my small script firefox-prefjs-surveyer.

Preference difference
PrefFirefox 140.0.4Firefox 141.0
browser.contentanalysis.interception_point.download.enabled undefined false
browser.contentblocking.customBlockList.preferences.ui.enabled false undefined
browser.contextual-services.contextId.rust-component.enabled false true
browser.download.deletePrivate undefined false
browser.download.deletePrivateChosen undefined false
browser.download.enableDeletePrivate undefined false
browser.ipProtection.enabled undefined false
browser.ml.chat.menu undefined true
browser.ml.chat.page undefined false
browser.ml.chat.page.footerBadge undefined true
browser.ml.chat.page.menuBadge undefined true
browser.ml.chat.prompts.1 {"id":"explain","l10nId":"genai-prompts-explain"} {"id":"explain","l10nId":"genai-prompts-explain","targeting":"contentType != 'page'"}
browser.ml.chat.prompts.2 {"id":"simplify","l10nId":"genai-prompts-simplify","targeting":"channel=='nightly'"} undefined
browser.ml.chat.prompts.3 {"id":"quiz","l10nId":"genai-prompts-quiz","targeting":"!provider|regExpMatch('gemini') || region == 'US'"} {"id":"quiz","l10nId":"genai-prompts-quiz","targeting":"(!provider|regExpMatch('gemini') || region == 'US') && contentType != 'page'"}
browser.ml.chat.prompts.4 {"id":"proofread", "l10nId":"genai-prompts-proofread"} {"id":"proofread", "l10nId":"genai-prompts-proofread","targeting":"contentType != 'page'"}
browser.newtabpage.activity-stream.discoverystream.sendToPocket.enabled true undefined
browser.newtabpage.activity-stream.discoverystream.shortcuts.personalization.enabled undefined false
browser.newtabpage.activity-stream.discoverystream.shortcuts.personalization.locale-config undefined en-US,en-GB,en-CA
browser.newtabpage.activity-stream.discoverystream.shortcuts.personalization.region-config undefined
browser.newtabpage.activity-stream.feeds.section.topstories.options {"api_key_pref":"extensions.pocket.oAuthConsumerKey","hidden":true,"provider_icon":"chrome://global/skin/icons/pocket.svg","provider_name":"Pocket","read_more_endpoint":"https://getpocket.com/explore/trending?src=fx_new_tab","stories_endpoint":"https://getpocket.cdn.mozilla.net/v3/firefox/global-recs?version=3&consumer_key=$apiKey&locale_lang=en-US&feed_variant=default_spocs_off","stories_referrer":"https://getpocket.com/recommendations","topics_endpoint":"https://getpocket.cdn.mozilla.net/v3/firefox/trending-topics?version=2&consumer_key=$apiKey&locale_lang=en-US","show_spocs":false} {"api_key_pref":"extensions.pocket.oAuthConsumerKey","hidden":true,"provider_icon":"chrome://global/skin/icons/help.svg","provider_name":"Pocket","read_more_endpoint":"https://getpocket.com/explore/trending?src=fx_new_tab","stories_endpoint":"https://getpocket.cdn.mozilla.net/v3/firefox/global-recs?version=3&consumer_key=$apiKey&locale_lang=en-US&feed_variant=default_spocs_off","stories_referrer":"https://getpocket.com/recommendations","topics_endpoint":"https://getpocket.cdn.mozilla.net/v3/firefox/trending-topics?version=2&consumer_key=$apiKey&locale_lang=en-US","show_spocs":false}
browser.newtabpage.activity-stream.feeds.smartshortcutsfeed undefined true
browser.newtabpage.activity-stream.feeds.trendingsearchfeed undefined true
browser.newtabpage.activity-stream.newtabLayouts.variant-a false undefined
browser.newtabpage.activity-stream.newtabLayouts.variant-b true undefined
browser.newtabpage.activity-stream.section.highlights.includePocket true undefined
browser.newtabpage.activity-stream.support.url https://support.mozilla.org/1/firefox/140.0.4/Linux/en-US/new-tab https://support.mozilla.org/1/firefox/141.0/Linux/en-US/new-tab
browser.newtabpage.activity-stream.system.trendingSearch.enabled undefined false
browser.newtabpage.activity-stream.trendingSearch.defaultSearchEngine undefined Google
browser.newtabpage.activity-stream.trendingSearch.enabled undefined true
browser.newtabpage.activity-stream.trendingSearch.variant undefined
browser.newtabpage.activity-stream.unifiedAds.adsFeed.spocs.enabled false undefined
browser.newtabpage.activity-stream.unifiedAds.adsFeed.tiles.enabled false undefined
browser.restoreWindowState.disabled undefined false
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 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
browser.screenshots.dir undefined
browser.screenshots.folderList undefined 1
browser.urlbar.amp.featureGate undefined false
browser.urlbar.quicksuggest.mlInitDelaySeconds undefined 0
browser.urlbar.suggest.amp undefined true
browser.urlbar.suggest.wikipedia undefined true
browser.urlbar.unitConversion.enabled false true
browser.urlbar.wikipedia.featureGate undefined false
devtools.aboutdebugging.showReduxActionsInConsole undefined false
devtools.responsive.dynamicToolbar.enabled undefined false
dom.dialog.light-dismiss.enabled false true
dom.element.commandfor.enabled undefined false
dom.element.invokers.enabled false undefined
dom.forms.search.esc undefined true
dom.intersection_observer.scroll_margin.enabled undefined true
dom.ipc.forkserver.enable false true
dom.performance.largest_contentful_paint.coarsened_rendertime_enabled undefined true
dom.storage_access.auto_grants.exclude_third_party_trackers false true
dom.text_fragments.create_text_fragment.exact_match_max_length undefined 200
dom.webgpu.service-workers.enabled undefined false
dom.webgpu.workers.enabled false undefined
dom.webnotifications.testing.force_storage_cleanup.enabled undefined false
editor.white_space_normalization.blink_compatible true undefined
extensions.cookie.rejectWhenInvalid undefined false
extensions.formautofill.addresses.supportedCountries US,CA,FR,DE US,CA,GB,FR,DE
extensions.formautofill.creditCards.supported detect on
image.natural-size-fallback.enabled false true
javascript.options.experimental.explicit_resource_management undefined true
javascript.options.wasm_exnref true undefined
javascript.options.wasm_gc false undefined
javascript.options.wasm_js_string_builtins true undefined
javascript.options.wasm_memory64 true undefined
javascript.options.wasm_multi_memory true undefined
javascript.options.wasm_tail_calls false undefined
layout.css.font-variant-emoji.enabled false true
layout.css.transition-behavior.enabled true undefined
layout.disable-pixel-alignment undefined false
layout.scroll.disable-pixel-alignment false undefined
logging.config.modules undefined
marionette.navigate-after-click.enabled undefined true
marionette.navigate-after-click.timeout undefined 50
media.gpu-process-encoder undefined false
media.peerconnection.sctp.default_max_streams undefined 2048
media.peerconnection.sctp.use_dcsctp undefined false
media.use-remote-encoder.audio undefined false
media.use-remote-encoder.video undefined false
media.utility-ffmpeg.enabled true undefined
media.utility-ffvpx.enabled true undefined
media.utility-opus.enabled true undefined
media.utility-vorbis.enabled true undefined
media.utility-wav.enabled true undefined
network.cookie.CHIPS.enabled false true
network.cookie.CHIPS.migrateDatabaseTarget 1 2
network.cookie.block_nameless_with_equal_char undefined true
network.cookie.cookieBehavior.trackerCookieBlocking true false
network.dns.native_https_timeout_mac 5000 undefined
network.dns.native_https_timeout_mac_msec undefined 5000
network.lna.block_trackers undefined false
network.lna.blocking undefined false
network.lna.enabled undefined true
nimbus.profilesdatastoreservice.read.enabled undefined false
privacy.bounceTrackingProtection.storage.maxPendingUpdates undefined 25
privacy.clearSiteDataHeader.cache.bfcache.enabled undefined true
privacy.dynamic_firstparty.use_site.include_port undefined false
privacy.restrict3rdpartystorage.heuristic.exclude_third_party_trackers false true
privacy.restrict3rdpartystorage.heuristic.navigation false true
privacy.restrict3rdpartystorage.heuristic.recently_visited true false
privacy.restrict3rdpartystorage.heuristic.window_open true false
privacy.trackingprotection.allow_list.baseline.enabled undefined true
privacy.trackingprotection.allow_list.convenience.enabled undefined true
privacy.trackingprotection.antifraud.annotate_channels undefined true
privacy.trackingprotection.antifraud.skip.enabled undefined false
privacy.trackingprotection.antifraud.skip.pbmode.enabled undefined true
remote.active-protocols 1 undefined
remote.experimental-parent-navigation.enabled false undefined
remote.parent-navigation.enabled undefined true
security.browser_xhtml_csp.report-only false undefined
security.csp.truncate_blocked_uri_for_frame_navigations true false
security.integrity_policy.enabled undefined false
security.sdr.mechanism undefined 0
security.tls.enable_certificate_compression_abridged undefined false
services.sync.prefs.sync-seen.browser.newtabpage.activity-stream.section.highlights.includePocket false undefined
services.sync.prefs.sync.browser.newtabpage.activity-stream.section.highlights.includePocket true undefined
sidebar.notification.badge.aichat undefined false
urlclassifier.disallow_completions goog-downloadwhite-digest256,base-track-digest256,mozstd-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 goog-downloadwhite-digest256,base-track-digest256,mozstd-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
urlclassifier.features.antifraud.annotate.allowlistTables undefined mozstd-trackwhite-digest256
urlclassifier.features.antifraud.annotate.blocklistTables undefined anti-fraud-track-digest256
widget.wayland.experimental.pip.enabled undefined true