This is difference between the default preference of Firefox 60.0 beta 5 and one of 59.0.1.

Preference difference
PrefFirefox 59.0.1Firefox 60.0 beta 5
app.normandy.api_urlundefinedhttps://normandy.cdn.mozilla.net/api/v1
app.normandy.dev_modeundefinedfalse
app.normandy.enabledundefinedtrue
app.normandy.logging.levelundefined50
app.normandy.run_interval_secondsundefined86400
app.normandy.shieldLearnMoreUrlundefinedhttps://support.mozilla.org/1/firefox/%VERSION%/%OS%/%LOCALE%/shield
app.shield.optoutstudies.enabledundefinedtrue
app.update.url.detailshttps://www.mozilla.org/%LOCALE%/firefox/noteshttps://www.mozilla.org/%LOCALE%/firefox/beta/notes
app.update.url.manualhttps://www.mozilla.org/firefox/https://www.mozilla.org/firefox/beta
browser.cache.offline.insecure.enableundefinedfalse
browser.chrome.errorReporter.enabledundefinedfalse
browser.chrome.errorReporter.infoURLundefinedhttps://support.mozilla.org/1/firefox/%VERSION%/%OS%/%LOCALE%/nightly-error-collection
browser.chrome.errorReporter.logLevelundefinedError
browser.chrome.errorReporter.projectIdundefined339
browser.chrome.errorReporter.publicKeyundefinedc709cb7a2c0b4f0882fcc84a5af161ec
browser.chrome.errorReporter.sampleRateundefined0.001
browser.chrome.errorReporter.submitUrlundefinedhttps://sentry.prod.mozaws.net/api/339/store/
browser.newtabpage.activity-stream.aboutHome.enabledtrueundefined
browser.newtabpage.activity-stream.enabledtrueundefined
browser.newtabpage.columns5undefined
browser.newtabpage.compactfalseundefined
browser.newtabpage.directory.sourcehttps://tiles.services.mozilla.com/v3/links/fetch/%LOCALE%/%CHANNEL%undefined
browser.newtabpage.enhancedtrueundefined
browser.newtabpage.introShownfalseundefined
browser.newtabpage.rows3undefined
browser.newtabpage.thumbnailPlaceholderfalseundefined
browser.places.useAsyncTransactionstrueundefined
browser.policies.enabledundefinedtrue
browser.safebrowsing.provider.mozilla.listsbase-track-digest256,mozstd-trackwhite-digest256,content-track-digest256,mozplugin-block-digest256,mozplugin2-block-digest256,block-flash-digest256,except-flash-digest256,allow-flashallow-digest256,except-flashallow-digest256,block-flashsubdoc-digest256,except-flashsubdoc-digest256,except-flashinfobar-digest256base-track-digest256,mozstd-trackwhite-digest256,content-track-digest256,mozplugin-block-digest256,mozplugin2-block-digest256,block-flash-digest256,except-flash-digest256,allow-flashallow-digest256,except-flashallow-digest256,block-flashsubdoc-digest256,except-flashsubdoc-digest256,except-flashinfobar-digest256,ads-track-digest256,social-track-digest256,analytics-track-digest256
browser.schedulePressure.timeoutMs1000300
browser.startup.blankWindowundefinedfalse
browser.urlbar.openintabundefinedfalse
device.sensors.ambientLight.enabledundefinedfalse
device.sensors.motion.enabledundefinedtrue
device.sensors.orientation.enabledundefinedtrue
device.sensors.proximity.enabledundefinedfalse
devtools.browserconsole.filter.cssundefinedfalse
devtools.browserconsole.filter.debugundefinedtrue
devtools.browserconsole.filter.netundefinedfalse
devtools.browserconsole.new-frontend-enabledundefinedfalse
devtools.browserconsole.ui.filterbarundefinedfalse
devtools.debugger.features.replayundefinedfalse
devtools.debugger.features.rootfalsetrue
devtools.devedition.promo.enabledfalsetrue
devtools.highlighter.writingModeAdjustfalseundefined
devtools.policy.disabledundefinedfalse
devtools.responsive.reloadConditions.touchSimulationundefinedfalse
devtools.responsive.reloadConditions.userAgentundefinedfalse
devtools.responsive.reloadNotification.enabledundefinedtrue
devtools.webide.monitorWebSocketURLws://localhost:9000undefined
dom.keyboardevent.keypress.dispatch_non_printable_keys_only_system_group_in_contentundefinedfalse
dom.moduleScripts.enabledfalsetrue
dom.push.alwaysConnectundefinedfalse
dom.registerContentHandler.enabledtruefalse
dom.registerProtocolHandler.insecure.enabledundefinedtrue
dom.secureelement.enabledfalseundefined
dom.serviceWorkers.update_delayundefined1000
dom.webdriver.enabledundefinedtrue
dom.webmidi.enabledundefinedfalse
dom.workers.enabledtrueundefined
editor.use_div_for_default_newlinesfalsetrue
extensions.alwaysUnpackfalseundefined
extensions.getAddons.compatOverides.urlundefinedhttps://services.addons.mozilla.org/api/v3/addons/compat-override/?guid=%IDS%&lang=%LOCALE%
extensions.getAddons.get.urlhttps://services.addons.mozilla.org/%LOCALE%/firefox/api/%API_VERSION%/search/guid:%IDS%?src=firefox&appOS=%OS%&appVersion=%VERSION%https://services.addons.mozilla.org/api/v3/addons/search/?guid=%IDS%&lang=%LOCALE%
extensions.getAddons.getWithPerformance.urlhttps://services.addons.mozilla.org/%LOCALE%/firefox/api/%API_VERSION%/search/guid:%IDS%?src=firefox&appOS=%OS%&appVersion=%VERSION%&tMain=%TIME_MAIN%&tFirstPaint=%TIME_FIRST_PAINT%&tSessionRestored=%TIME_SESSION_RESTORED%undefined
extensions.hotfix.cert.checkAttributestrueundefined
extensions.hotfix.certs.1.sha1Fingerprint91:53:98:0C:C1:86:DF:47:8F:35:22:9E:11:C9:A7:31:04:49:A1:AAundefined
extensions.hotfix.certs.2.sha1Fingerprint39:E7:2B:7A:5B:CF:37:78:F9:5D:4A:E0:53:2D:2F:3D:68:53:C5:60undefined
extensions.hotfix.idfirefox-hotfix@mozilla.orgundefined
extensions.interposition.enabledtrueundefined
extensions.interposition.prefetchingtrueundefined
extensions.langpacks.signatures.requiredundefinedfalse
extensions.screenshots.upload-disabledundefinedfalse
extensions.webextensions.restrictedDomainsundefinedaccounts-static.cdn.mozilla.net,accounts.firefox.com,addons.cdn.mozilla.net,addons.mozilla.org,api.accounts.firefox.com,content.cdn.mozilla.net,content.cdn.mozilla.net,discovery.addons.mozilla.org,input.mozilla.org,install.mozilla.org,oauth.accounts.firefox.com,profile.accounts.firefox.com,support.mozilla.org,sync.services.mozilla.com,testpilot.firefox.com
general.document_open_conversion_depth_limitundefined20
geo.provider.use_gpsdfalseundefined
geo.wifi.urihttps://www.googleapis.com/geolocation/v1/geolocate?key=%GOOGLE_API_KEY%https://location.services.mozilla.com/v1/geolocate?key=%MOZILLA_API_KEY%
gfx.font_loader.families_per_slice3undefined
gfx.webrender.blob-images21
gfx.webrender.hit-testfalsetrue
identity.fxaccounts.enabledundefinedtrue
identity.fxaccounts.remote.connectdevice.urihttps://accounts.firefox.com/connect_another_device?service=sync&context=fx_desktop_v3undefined
identity.fxaccounts.remote.email.urihttps://accounts.firefox.com/?service=sync&context=fx_desktop_v3&action=emailundefined
identity.fxaccounts.remote.force_auth.urihttps://accounts.firefox.com/force_auth?service=sync&context=fx_desktop_v3undefined
identity.fxaccounts.remote.rootundefinedhttps://accounts.firefox.com/
identity.fxaccounts.remote.signin.urihttps://accounts.firefox.com/signin?service=sync&context=fx_desktop_v3undefined
identity.fxaccounts.remote.signup.urihttps://accounts.firefox.com/signup?service=sync&context=fx_desktop_v3undefined
identity.fxaccounts.remote.webchannel.urihttps://accounts.firefox.com/undefined
identity.fxaccounts.settings.devices.urihttps://accounts.firefox.com/settings/clients?service=sync&context=fx_desktop_v3undefined
identity.fxaccounts.settings.urihttps://accounts.firefox.com/settings?service=sync&context=fx_desktop_v3undefined
image.animated.decode-on-demand.batch-sizeundefined6
image.animated.decode-on-demand.threshold-kbundefined20480
image.mem.animated.use_heapundefinedfalse
image.mem.volatile.min_threshold_kbundefined-1
image.multithreaded_decoding.idle_timeoutundefined600000
javascript.options.array_prototype_valuesundefinedtrue
javascript.options.spectre.jit_to_C++_callsundefinedtrue
javascript.options.spectre.object_mitigations.barriersundefinedtrue
javascript.options.spectre.object_mitigations.miscundefinedtrue
javascript.options.spectre.string_mitigationsundefinedtrue
javascript.options.spectre.value_maskingundefinedtrue
layers.omtp.dump-captureundefinedfalse
layout.css.individual-transform.enabledundefinedfalse
layout.css.moz-document.content.enabledtruefalse
layout.css.paint-order.enabledundefinedtrue
layout.css.servo.chrome.enabledfalsetrue
layout.css.stylo-blocklist.blocked_domainsundefined
layout.css.stylo-blocklist.enabledfalseundefined
layout.display-list.retainfalsetrue
layout.word_select.stop_at_underscoreundefinedfalse
marionette.debugging.clicktostartundefinedfalse
marionette.enabledundefinedfalse
media.cubeb.sandboxundefinedtrue
media.getusermedia.camera.off_while_disabled.delay_msundefined3000
media.getusermedia.camera.off_while_disabled.enabledundefinedtrue
media.getusermedia.microphone.off_while_disabled.delay_msundefined3000
media.getusermedia.microphone.off_while_disabled.enabledundefinedtrue
network.dns.native-is-localhostundefinedfalse
network.ftp.enabledundefinedtrue
network.trr.allow-rfc1918undefinedfalse
network.trr.blacklist-durationundefined259200
network.trr.bootstrapAddressundefined
network.trr.confirmationNSundefinedexample.com
network.trr.credentialsundefined
network.trr.early-AAAAundefinedfalse
network.trr.modeundefined0
network.trr.request-timeoutundefined3000
network.trr.uriundefined
network.trr.useGETundefinedfalse
network.trr.wait-for-portalundefinedtrue
print.use_simplify_pagefalsetrue
privacy.resistFingerprinting.reduceTimerPrecision.jitterundefinedtrue
security.insecure_connection_text.enabledundefinedfalse
security.insecure_connection_text.pbmode.enabledundefinedfalse
security.mixed_content.block_object_subrequestfalsetrue
security.mixed_content.upgrade_display_contentundefinedfalse
security.pki.distrust_ca_policyundefined1
security.sandbox.content.level34
security.sandbox.content.tempDirSuffixundefined
security.tls.version.max34
security.webauth.webauthnfalsetrue
security.xcto_nosniff_block_imagesfalseundefined
services.sync.engine.bookmarks.bufferundefinedfalse
services.sync.engine.bookmarks.validation.enabledundefinedtrue
services.sync.engine.passwords.validation.enabledundefinedtrue
services.sync.engine.passwords.validation.intervalundefined86400
services.sync.engine.passwords.validation.maxRecordsundefined1000
services.sync.engine.passwords.validation.percentageChanceundefined10
services.sync.errorhandler.networkFailureReportTimeout1209600undefined
services.sync.prefs.sync.browser.newtabpage.enhancedtrueundefined
services.sync.prefs.sync.browser.urlbar.matchBucketsundefinedtrue
services.sync.prefs.sync.privacy.resistFingerprinting.reduceTimerPrecision.jitterundefinedtrue
services.sync.scheduler.eolInterval604800undefined
signed.applets.codebase_principal_supportfalseundefined
svg.paint-order.enabledtrueundefined
urlclassifier.disallow_completionstest-malware-simple,test-harmful-simple,test-phish-simple,test-unwanted-simple,test-track-simple,test-trackwhite-simple,test-block-simple,goog-downloadwhite-digest256,base-track-digest256,mozstd-trackwhite-digest256,content-track-digest256,mozplugin-block-digest256,mozplugin2-block-digest256,block-flash-digest256,except-flash-digest256,allow-flashallow-digest256,except-flashallow-digest256,block-flashsubdoc-digest256,except-flashsubdoc-digest256,except-flashinfobar-digest256,goog-passwordwhite-prototest-malware-simple,test-harmful-simple,test-phish-simple,test-unwanted-simple,test-track-simple,test-trackwhite-simple,test-block-simple,goog-downloadwhite-digest256,base-track-digest256,mozstd-trackwhite-digest256,content-track-digest256,mozplugin-block-digest256,mozplugin2-block-digest256,block-flash-digest256,except-flash-digest256,allow-flashallow-digest256,except-flashallow-digest256,block-flashsubdoc-digest256,except-flashsubdoc-digest256,except-flashinfobar-digest256,goog-passwordwhite-proto,ads-track-digest256,social-track-digest256,analytics-track-digest256
view_source.tabtrueundefined
Default pref Javascript files
PrefFirefox 59.0.1Firefox 60.0 beta 5
browser/omni.ja.d/defaults/preferences/debugger.jspresentpresent
browser/omni.ja.d/defaults/preferences/devtools-startup-prefs.jspresentpresent
browser/omni.ja.d/defaults/preferences/devtools.jspresentpresent
browser/omni.ja.d/defaults/preferences/firefox-branding.jspresentpresent
browser/omni.ja.d/defaults/preferences/firefox-l10n.jspresentpresent
browser/omni.ja.d/defaults/preferences/firefox.jspresentpresent
browser/omni.ja.d/defaults/preferences/webide-prefs.jspresentpresent
omni.ja.d/defaults/pref/marionette.jspresentpresent
omni.ja.d/defaults/pref/services-sync.jspresentpresent
omni.ja.d/greprefs.jspresentpresent