diff --git a/lib/Launcher.js b/lib/Launcher.js
index 9f3e2ac004404..bc3796f8adb3d 100644
--- a/lib/Launcher.js
+++ b/lib/Launcher.js
@@ -515,19 +515,211 @@ class FirefoxLauncher {
    */
   async _createProfile(extraPrefs) {
     const profilePath = await mkdtempAsync(path.join(os.tmpdir(), 'puppeteer_dev_firefox_profile-'));
-    const prefsJs = [];
-    const userJs = [];
-    const preferences = {
+    const prefsJS = [];
+    const userJS = [];
+    const server = 'dummy.test';
+    const defaultPreferences = {
+      // Make sure Shield doesn't hit the network.
+      'app.normandy.api_url': '',
+      // Disable Firefox old build background check
+      'app.update.checkInstallTime': false,
+      // Disable automatically upgrading Firefox
+      'app.update.disabledForTesting': true,
+
+      // Increase the APZ content response timeout to 1 minute
+      'apz.content_response_timeout': 60000,
+
+      // Prevent various error message on the console
+      // jest-puppeteer asserts that no error message is emitted by the console
+      'browser.contentblocking.features.standard': '-tp,tpPrivate,cookieBehavior0,-cm,-fp',
+
+
+      // Enable the dump function: which sends messages to the system
+      // console
+      // https://bugzilla.mozilla.org/show_bug.cgi?id=1543115
+      'browser.dom.window.dump.enabled': true,
+      // Disable topstories
+      'browser.newtabpage.activity-stream.feeds.section.topstories': false,
+      // Always display a blank page
+      'browser.newtabpage.enabled': false,
+      // Background thumbnails in particular cause grief: and disabling
+      // thumbnails in general cannot hurt
+      'browser.pagethumbnails.capturing_disabled': true,
+
+      // Disable safebrowsing components.
+      'browser.safebrowsing.blockedURIs.enabled': false,
+      'browser.safebrowsing.downloads.enabled': false,
+      'browser.safebrowsing.malware.enabled': false,
+      'browser.safebrowsing.passwords.enabled': false,
+      'browser.safebrowsing.phishing.enabled': false,
+
+      // Disable updates to search engines.
+      'browser.search.update': false,
+      // Do not restore the last open set of tabs if the browser has crashed
+      'browser.sessionstore.resume_from_crash': false,
+      // Skip check for default browser on startup
+      'browser.shell.checkDefaultBrowser': false,
+
+      // Disable newtabpage
+      'browser.startup.homepage': 'about:blank',
+      // Do not redirect user when a milstone upgrade of Firefox is detected
+      'browser.startup.homepage_override.mstone': 'ignore',
+      // Start with a blank page about:blank
+      'browser.startup.page': 0,
+
+      // Do not allow background tabs to be zombified on Android: otherwise for
+      // tests that open additional tabs: the test harness tab itself might get
+      // unloaded
+      'browser.tabs.disableBackgroundZombification': false,
+      // Do not warn when closing all other open tabs
+      'browser.tabs.warnOnCloseOtherTabs': false,
+      // Do not warn when multiple tabs will be opened
+      'browser.tabs.warnOnOpen': false,
+
+      // Disable the UI tour.
+      'browser.uitour.enabled': false,
+      // Turn off search suggestions in the location bar so as not to trigger
+      // network connections.
+      'browser.urlbar.suggest.searches': false,
+      // Disable first run splash page on Windows 10
+      'browser.usedOnWindows10.introURL': '',
+      // Do not warn on quitting Firefox
+      'browser.warnOnQuit': false,
+
+      // Do not show datareporting policy notifications which can
+      // interfere with tests
+      'datareporting.healthreport.about.reportUrl': `http://${server}/dummy/abouthealthreport/`,
+      'datareporting.healthreport.documentServerURI': `http://${server}/dummy/healthreport/`,
+      'datareporting.healthreport.logging.consoleEnabled': false,
+      'datareporting.healthreport.service.enabled': false,
+      'datareporting.healthreport.service.firstRun': false,
+      'datareporting.healthreport.uploadEnabled': false,
+      'datareporting.policy.dataSubmissionEnabled': false,
+      'datareporting.policy.dataSubmissionPolicyAccepted': false,
+      'datareporting.policy.dataSubmissionPolicyBypassNotification': true,
+
+      // DevTools JSONViewer sometimes fails to load dependencies with its require.js.
+      // This doesn't affect Puppeteer but spams console (Bug 1424372)
+      'devtools.jsonview.enabled': false,
+
+      // Disable popup-blocker
+      'dom.disable_open_during_load': false,
+
+      // Enable the support for File object creation in the content process
+      // Required for |Page.setFileInputFiles| protocol method.
+      'dom.file.createInChild': true,
+
+      // Disable the ProcessHangMonitor
+      'dom.ipc.reportProcessHangs': false,
+
+      // Disable slow script dialogues
+      'dom.max_chrome_script_run_time': 0,
+      'dom.max_script_run_time': 0,
+
+      // Only load extensions from the application and user profile
+      // AddonManager.SCOPE_PROFILE + AddonManager.SCOPE_APPLICATION
+      'extensions.autoDisableScopes': 0,
+      'extensions.enabledScopes': 5,
+
+      // Disable metadata caching for installed add-ons by default
+      'extensions.getAddons.cache.enabled': false,
+
+      // Disable installing any distribution extensions or add-ons.
+      'extensions.installDistroAddons': false,
+
+      // Disabled screenshots extension
+      'extensions.screenshots.disabled': true,
+
+      // Turn off extension updates so they do not bother tests
+      'extensions.update.enabled': false,
+
+      // Turn off extension updates so they do not bother tests
+      'extensions.update.notifyUser': false,
+
+      // Make sure opening about:addons will not hit the network
+      'extensions.webservice.discoverURL': `http://${server}/dummy/discoveryURL`,
+
+      // Allow the application to have focus even it runs in the background
+      'focusmanager.testmode': true,
+      // Disable useragent updates
+      'general.useragent.updates.enabled': false,
+      // Always use network provider for geolocation tests so we bypass the
+      // macOS dialog raised by the corelocation provider
+      'geo.provider.testing': true,
+      // Do not scan Wifi
+      'geo.wifi.scan': false,
+      // No hang monitor
+      'hangmonitor.timeout': 0,
+      // Show chrome errors and warnings in the error console
+      'javascript.options.showInConsole': true,
+
+      // Disable download and usage of OpenH264: and Widevine plugins
+      'media.gmp-manager.updateEnabled': false,
+      // Prevent various error message on the console
+      // jest-puppeteer asserts that no error message is emitted by the console
+      'network.cookie.cookieBehavior': 0,
+
+      // Do not prompt for temporary redirects
+      'network.http.prompt-temp-redirect': false,
+
+      // Disable speculative connections so they are not reported as leaking
+      // when they are hanging around
+      'network.http.speculative-parallel-limit': 0,
+
+      // Do not automatically switch between offline and online
+      'network.manage-offline-status': false,
+
+      // Make sure SNTP requests do not hit the network
+      'network.sntp.pools': server,
+
+      // Disable Flash.
+      'plugin.state.flash': 0,
+
+      'privacy.trackingprotection.enabled': false,
+
+      // Enable Remote Agent
       // https://bugzilla.mozilla.org/show_bug.cgi?id=1544393
       'remote.enabled': true,
-      // https://bugzilla.mozilla.org/show_bug.cgi?id=1543115
-      'browser.dom.window.dump.enabled': true
+
+      // Don't do network connections for mitm priming
+      'security.certerrors.mitm.priming.enabled': false,
+      // Local documents have access to all other local documents,
+      // including directory listings
+      'security.fileuri.strict_origin_policy': false,
+      // Do not wait for the notification button security delay
+      'security.notification_enable_delay': 0,
+
+      // Ensure blocklist updates do not hit the network
+      'services.settings.server': `http://${server}/dummy/blocklist/`,
+
+      // Do not automatically fill sign-in forms with known usernames and
+      // passwords
+      'signon.autofillForms': false,
+      // Disable password capture, so that tests that include forms are not
+      // influenced by the presence of the persistent doorhanger notification
+      'signon.rememberSignons': false,
+
+      // Disable first-run welcome page
+      'startup.homepage_welcome_url': 'about:blank',
+
+      // Disable first-run welcome page
+      'startup.homepage_welcome_url.additional': '',
+
+      // Disable browser animations (tabs, fullscreen, sliding alerts)
+      'toolkit.cosmeticAnimations.enabled': false,
+
+      // We want to collect telemetry, but we don't want to send in the results
+      'toolkit.telemetry.server': `https://${server}/dummy/telemetry/`,
+      // Prevent starting into safe mode after application crashes
+      'toolkit.startup.max_resumed_crashes': -1,
+
     };
-    Object.assign(preferences, extraPrefs);
-    for (const [key, value] of Object.entries(preferences))
-      userJs.push(`user_pref(${JSON.stringify(key)}, ${JSON.stringify(value)});`);
-    await writeFileAsync(path.join(profilePath, 'user.js'), userJs.join('\n'));
-    await writeFileAsync(path.join(profilePath, 'prefs.js'), prefsJs.join('\n'));
+
+    Object.assign(defaultPreferences, extraPrefs);
+    for (const [key, value] of Object.entries(defaultPreferences))
+      userJS.push(`user_pref(${JSON.stringify(key)}, ${JSON.stringify(value)});`);
+    await writeFileAsync(path.join(profilePath, 'user.js'), userJS.join('\n'));
+    await writeFileAsync(path.join(profilePath, 'prefs.js'), prefsJS.join('\n'));
     return profilePath;
   }
 }