This article shows the difference between the default preferences of Firefox 153.0 beta 2 and Firefox 152.0.1. The diff table below is generated using my small script firefox-prefjs-surveyer.

Preference difference
PrefFirefox 152.0.1Firefox 153.0 beta 2
app.normandy.test-prefs.bool undefined false
app.normandy.test-prefs.integer undefined 0
app.normandy.test-prefs.string undefined
app.releaseNotesURL https://www.firefox.com/%LOCALE%/firefox/%VERSION%/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-desktop&utm_campaign=whatsnew https://www.firefox.com/%LOCALE%/firefox/%VERSION%beta/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-desktop&utm_campaign=whatsnew
app.releaseNotesURL.aboutDialog https://www.firefox.com/%LOCALE%/firefox/%VERSION%/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-desktop&utm_campaign=about-dialog https://www.firefox.com/%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.autoscroll.scroll_wheel_cooldown undefined 500
apz.fastpath_apz_aware_listener.enabled undefined true
browser.backup.enabled_on.profiles {} []
browser.cache.disk.encryption.enabled undefined false
browser.cache.disk.encryption.key undefined
browser.cache.disk.index.min_dump_interval_ms undefined 20000
browser.cache.disk.index.min_unwritten_changes undefined 300
browser.cache.disk.index.update_start_delay_ms undefined 50000
browser.crashReports.cleanupCheck.enabled undefined true
browser.ml.embedGen.textEmbeddingFeatureModel undefined
browser.ml.embedGen.textEmbeddingSize undefined 384
browser.newtabpage.activity-stream.discoverystream.thumbsUpDown.region-thumbs-config US US, CA
browser.newtabpage.activity-stream.hideLogo undefined false
browser.newtabpage.activity-stream.logo.variation undefined
browser.newtabpage.activity-stream.privacyInfo.url https://support.mozilla.org/1/firefox/152.0.1/Linux/en-US/sponsor-privacy https://support.mozilla.org/1/firefox/153.0/Linux/en-US/sponsor-privacy
browser.newtabpage.activity-stream.sectionsLearnMore.url undefined https://support.mozilla.org/1/firefox/153.0/Linux/en-US/firefox-new-tab-personalization
browser.newtabpage.activity-stream.sports.worldCup.liveEndpoint undefined https://merino.services.mozilla.com/api/v1/wcs/live
browser.newtabpage.activity-stream.sports.worldCup.watchLiveEndpoint undefined https://merino.services.mozilla.com/api/v1/wcs/watch-links
browser.newtabpage.activity-stream.support.url https://support.mozilla.org/1/firefox/152.0.1/Linux/en-US/new-tab https://support.mozilla.org/1/firefox/153.0/Linux/en-US/new-tab
browser.newtabpage.activity-stream.telemetry.ut.events false true
browser.newtabpage.activity-stream.widgets.clocks.size large
browser.newtabpage.activity-stream.widgets.defaultSize large medium
browser.newtabpage.activity-stream.widgets.row.expanded undefined false
browser.newtabpage.activity-stream.widgets.sports.forceLiveDataTrustable undefined false
browser.newtabpage.activity-stream.widgets.sportsWidget.celebrations.enabled undefined false
browser.newtabpage.activity-stream.widgets.sportsWidget.celebrations.windowMs undefined 86400000
browser.newtabpage.activity-stream.widgets.sportsWidget.pollIdleMs undefined 21600000
browser.newtabpage.activity-stream.widgets.sportsWidget.pollLiveMs undefined 180000
browser.newtabpage.activity-stream.widgets.sportsWidget.pollMatchDayMs undefined 1800000
browser.newtabpage.activity-stream.widgets.sportsWidget.pollPregameLeadMs undefined 600000
browser.privatebrowsing.felt-privacy-v1 true undefined
browser.sessionstore.log.appender.file.logOnSuccess false true
browser.sessionstore.loglevel Warn Debug
browser.shareqrcode.embed_logo undefined true
browser.shareqrcode.enabled false true
browser.smartwindow.allowTables true undefined
browser.smartwindow.apiKey undefined
browser.smartwindow.endpoint https://mlpa-prod-prod-mozilla.global.ssl.fastly.net/v1 undefined
browser.smartwindow.firstrun.modelChoice undefined
browser.smartwindow.model undefined
browser.smartwindow.preferences.endpoint undefined
browser.unexpectedScriptLoad.logLevel Warn undefined
devtools.debugger.log.verbose false undefined
dom.audio_session.enabled undefined false
dom.audio_session.state_enabled undefined false
dom.event.keypress.key.allow_lone_surrogate true false
dom.fetch.allow_force_allowed_dtd undefined false
dom.headingoffset.enabled undefined false
dom.lift_select_parser_restrictions.enabled false undefined
dom.media-pip.enabled undefined true
dom.pointer-lock.native-lock.enabled undefined true
dom.script_loader.external_scripts.speculate_link_preload.enabled false true
dom.security.sanitizer.processing-instructions undefined false
dom.security.unexpected_system_load_telemetry_enabled false true
dom.timeout.defer_during_load true false
dom.webgpu.enabled false true
dom.webgpu.service-workers.enabled false true
dom.workers.throttling.enabled false true
extensions.formautofill.useml undefined false
extensions.webcompat-reporter.enabled false true
extensions.webextensions.fileSchemeAccess.requireOptIn undefined true
intl.ime.content_observer.notifications.position_change.ticks_after_scrolling undefined 10
javascript.options.experimental.error_stack_trace_limit undefined true
javascript.options.experimental.import_text undefined true
javascript.options.experimental.intl_locale_info undefined true
javascript.options.experimental.source_phase_imports undefined true
javascript.options.experimental.source_phase_imports.test262_module_source undefined false
javascript.options.legacy_tosource_lookup false undefined
javascript.options.tests.fuzzing-unsafe-pref undefined false
javascript.options.wasm_components undefined false
javascript.options.wasm_js_promise_integration false true
layout.abspos.fragment-aware-inline-cb.enabled undefined true
layout.abspos.fragmentainer-aware-positioning.enabled true undefined
layout.css.background-clip.border-area.enabled undefined false
layout.css.corner-shape.enabled undefined false
layout.css.fake-webkit-scrollbar.enabled false true
layout.css.gamut-mapping.method undefined 0
layout.css.heading-selector.enabled false undefined
layout.css.letter-spacing.model 0 2
layout.css.link-parameters.enabled undefined false
layout.css.scroll-driven-animations.viewtimeline.enabled false undefined
layout.css.stylesheet-cache.timeout_ms undefined 15000
layout.css.tree-counting-functions.enabled undefined false
layout.dynamic-reflow-roots.enabled false true
mathml.legacy_mathvariant_attribute.disabled false true
mathml.mathspace_names.disabled false true
media.contextmenu.video-overlay-detection false true
media.hardware-video-decoding-vulkan.direct-export.enabled undefined false
media.mediacapabilities.webrtc.enabled false true
media.webrtc.simulcast.vp9.enabled false true
memory.phc.size_kb 1152 16384
network.android_doh.start_in_confirmation_failed_state undefined true
network.auth.use_redirect_for_retries false true
network.cache.no_vary_search undefined false
network.cookie.cookieBehavior.trackerCookieBlocking false undefined
network.essential_domains_fallback false true
network.http.0rtt_force_txn_gone_for_testing undefined false
network.http.http3.retry_different_ip_family false 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.exclude_dns_suffix_in_mode_trronly undefined false
network.trr.idle_timeout_for_http3_conn 30 400
network.trr.start-confirmation-in-failed-state undefined false
pdfjs.enableSelectionRendering undefined true
pdfjs.postMessageAfterPrintCallback undefined false
places.semanticHistory.embeddingType undefined static
places.semanticHistory.featureGate false true
privacy.resistFingerprinting.randomization.daily_reset.enabled false true
privacy.resistFingerprinting.randomization.daily_reset.private.enabled false true
privacy.trackingprotection.content.annotation.engines undefined test_annotate
privacy.trackingprotection.content.annotation.engines.pbmode undefined
privacy.trackingprotection.content.annotation.list_names undefined
privacy.trackingprotection.content.protection.engines undefined test_block
privacy.trackingprotection.content.protection.engines.pbmode undefined
privacy.trackingprotection.content.protection.list_names undefined
security.block_parent_unrestricted_js_loads.temporary false undefined
security.chrome_baseline_csp.enabled undefined true
security.disallow_non_local_systemprincipal_in_tests undefined false
security.hide_parent_unrestricted_js_loads_warning.temporary false undefined
security.parent_unrestricted_js_loads.skip_jshacks false undefined
security.qwacs.enabled false true
security.ssl3.ecdhe_ecdsa_aes_256_sha true false
services.sync.engine.bookmarks.validation.enabled undefined true
services.sync.engine.passwords.validation.enabled undefined true
sidebar.openTabsPanel.enabled undefined false
toolkit.perfetto.enabled undefined false
toolkit.telemetry.enabled false true
ui.new-webcompat-reporter.send-more-info-link false true
webgl.1.allow-core-profiles false undefined
widget.gtk.rounded-bottom-corners.enabled false true
widget.wayland.coordinates-scale.enabled undefined false
widget.wayland.native-data-session undefined false