diff --git a/karma-base.js b/karma-base.js
index f0f90ad93b..32c6e6cad5 100644
--- a/karma-base.js
+++ b/karma-base.js
@@ -204,6 +204,50 @@ var osmtiles_middleware = function (config) {
   };
 };
 
+/* Reduce the number of external connections Chrome makes. */
+var ChromeFlags = [
+  '--no-sandbox',  // necessary to run tests in a docker
+  '--no-pings',    // no auditing pings
+  '--disable-background-networking',
+  '--disable-component-extensions-with-background-pages'
+];
+
+/* By default, when Firefox starts it makes many connections to sites like
+ * mozilla.org, yahoo.com, google.com, etc.  This limits these connections (but
+ * doesn't eliminate them completely, especially when accessing the 2d canvas).
+ * See
+ * https://support.mozilla.org/en-US/kb/how-stop-firefox-making-automatic-connections
+ */
+var FirefoxPrefs = {
+  'browser.aboutHomeSnippets.updateUrl': '',
+  'browser.casting.enabled': false,
+  'browser.library.activity-stream.enabled': false,
+  'browser.newtabpage.activity-stream.enabled': false,
+  'browser.search.geoip.url': '',
+  'browser.selfsupport.enabled': false,
+  'browser.selfsupport.url': '',
+  'browser.startup.homepage_override.mstone': 'ignore',
+  'extensions.getAddons.cache.enabled': false,
+  'extensions.pocket.enabled': false,
+  'extensions.update.enabled': false,
+  'network.captive-portal-service.enabled': false,
+  'network.dns.disablePrefetch': true,
+  'network.http.speculative-parallel-limit': 0,
+  'network.prefetch-next': false,
+  // these further limit firefox connections
+  'browser.safebrowsing.provider.mozilla.gethashURL': '',
+  'browser.safebrowsing.provider.mozilla.updateURL': '',
+  'browser.safebrowsing.provider.google.gethashURL': '',
+  'browser.safebrowsing.provider.google.updateURL': '',
+  'browser.safebrowsing.provider.google4.dataSharingURL': '',
+  'browser.safebrowsing.provider.google4.gethashURL': '',
+  'browser.safebrowsing.provider.google4.updateURL': '',
+  'datareporting.healthreport.uploadEnabled': false,
+  'datareporting.policy.dataSubmissionEnabled': false,
+  'media.gmp-gmpopenh264.autoupdate': false,
+  'media.gmp-manager.url': ''
+};
+
 module.exports = function (config) {
   var newConfig = {
     autoWatch: false,
@@ -231,51 +275,50 @@ module.exports = function (config) {
     customLaunchers: {
       ChromeHeadlessTouch: {
         base: 'ChromeHeadless',
-        flags: [
-          '--no-sandbox',  // necessary to run tests in a docker
-          '--no-pings',    // no auditing pings
+        flags: ChromeFlags.concat([
           '--touch-events'
-        ]
+        ])
       },
       ChromeFull: {
         base: 'Chrome',
-        flags: [
-          '--no-sandbox',  // necessary to run tests in a docker
-          '--no-pings',    // no auditing pings
+        flags: ChromeFlags.concat([
           '--device-scale-factor=1',
           '--window-position=0,0',
           '--start-fullscreen',
           '--kiosk',
           '--incognito'
-        ]
+        ])
       },
       ChromeWithProxy: {
         // inheriting from ChromeFull ignores the flags in this entry, so we
         // need to inherit from Chrome
         base: 'Chrome',
-        flags: [
-          '--no-sandbox',  // necessary to run tests in a docker
-          '--no-pings',    // no auditing pings
+        flags: ChromeFlags.concat([
           '--device-scale-factor=1',
           '--window-position=0,0',
           '--start-fullscreen',
           '--kiosk',
           '--incognito',
+          '--translate-script-url=""',
           '--proxy-pac-url=' + config.protocol + '//' + config.hostname + ':' + config.port + '/testdata/proxy-for-tests.pac'
-        ]
+        ])
       },
-      FirefoxTouch: {
-        base: 'Firefox',
-        prefs: {
+      FirefoxHeadlessTouch: {
+        base: 'FirefoxHeadless',
+        prefs: Object.assign({
+          // enable touch
           'dom.w3c_touch_events.enabled': 1
-        }
+        }, FirefoxPrefs)
       },
       FirefoxWithProxy: {
-        base: 'FirefoxTouch',
-        prefs: {
+        base: 'Firefox',
+        prefs: Object.assign({
+          // enable proxy
           'network.proxy.type': 2,
-          'network.proxy.autoconfig_url': config.protocol + '//' + config.hostname + ':' + config.port + '/testdata/proxy-for-tests.pac'
-        }
+          'network.proxy.autoconfig_url': config.protocol + '//' + config.hostname + ':' + config.port + '/testdata/proxy-for-tests.pac',
+          // enable touch
+          'dom.w3c_touch_events.enabled': 1
+        }, FirefoxPrefs)
       }
     },
     browserNoActivityTimeout: 30000,
diff --git a/package.json b/package.json
index f8a9e1a522..2691469a1a 100644
--- a/package.json
+++ b/package.json
@@ -57,7 +57,7 @@
     "karma": "^0.13.22",
     "karma-chrome-launcher": "^2.2.0",
     "karma-coverage": "^1.0.0",
-    "karma-firefox-launcher": "^1.0.1",
+    "karma-firefox-launcher": "^1.1.0",
     "karma-jasmine": "^1.0.2",
     "karma-jasmine-html-reporter": "^0.2.0",
     "karma-phantomjs-launcher": "^1.0.0",
@@ -97,15 +97,15 @@
     "build-website-tutorials": "node tutorials/build-website.js && webpack --config webpack-website-tutorials.config.js",
     "lint": "eslint --cache .",
     "puglint": "pug-lint src examples",
-    "test": "GEOJS_TEST_CASE=tests/test-unit.js karma start karma-cov.conf.js --single-run --browsers ChromeHeadlessTouch,FirefoxTouch,PhantomJS",
-    "test-all": "GEOJS_TEST_CASE=tests/test-unit.js karma start karma-cov.conf.js --single-run --browsers ChromeHeadlessTouch,FirefoxTouch,PhantomJS",
+    "test": "GEOJS_TEST_CASE=tests/test-unit.js karma start karma-cov.conf.js --single-run --browsers ChromeHeadlessTouch,FirefoxHeadlessTouch,PhantomJS",
+    "test-all": "GEOJS_TEST_CASE=tests/test-unit.js karma start karma-cov.conf.js --single-run --browsers ChromeHeadlessTouch,FirefoxHeadlessTouch,PhantomJS",
     "start": "karma start karma.conf.js",
     "glci": "GEOJS_TEST_CASE=tests/test-gl.js karma start karma-cov.conf.js --single-run --browsers ChromeHeadlessTouch",
-    "glci-all": "GEOJS_TEST_CASE=tests/test-gl.js karma start karma-cov.conf.js --single-run --browsers ChromeHeadlessTouch,FirefoxTouch",
+    "glci-all": "GEOJS_TEST_CASE=tests/test-gl.js karma start karma-cov.conf.js --single-run --browsers ChromeHeadlessTouch,FirefoxHeadlessTouch",
     "headedci": "GEOJS_TEST_CASE=tests/test-headed.js karma start karma-cov.conf.js --single-run --browsers ChromeWithProxy",
     "headedci-all": "GEOJS_TEST_CASE=tests/test-headed.js karma start karma-cov.conf.js --single-run --browsers ChromeWithProxy,FirefoxWithProxy",
     "tutorialsci": "GEOJS_TEST_CASE=tests/tutorials.js karma start karma-cov.conf.js --single-run --browsers ChromeHeadlessTouch,PhantomJS",
-    "tutorialsci-all": "GEOJS_TEST_CASE=tests/tutorials.js karma start karma-cov.conf.js --single-run --browsers ChromeHeadlessTouch,FirefoxTouch,PhantomJS",
+    "tutorialsci-all": "GEOJS_TEST_CASE=tests/tutorials.js karma start karma-cov.conf.js --single-run --browsers ChromeHeadlessTouch,FirefoxHeadlessTouch,PhantomJS",
     "test-webgl": "GEOJS_TEST_CASE=tests/test-gl.js karma start karma-cov.conf.js --single-run --browsers ChromeHeadlessTouch",
     "test-headed": "GEOJS_TEST_CASE=tests/test-headed.js xvfb-run -s '-ac -screen 0 1280x1024x24' karma start karma-cov.conf.js --single-run --browsers ChromeWithProxy",
     "codecov": "codecov",