diff --git a/tfjs-backend-wasm/cloudbuild.yml b/tfjs-backend-wasm/cloudbuild.yml
index 0eb676044f1..59bfffaf0d9 100644
--- a/tfjs-backend-wasm/cloudbuild.yml
+++ b/tfjs-backend-wasm/cloudbuild.yml
@@ -44,7 +44,7 @@ steps:
   id: 'test-wasm'
   args: ['test-ci']
   waitFor: ['yarn', 'build-deps', 'build', 'lint']
-  env: ['BROWSERSTACK_USERNAME=deeplearnjs1']
+  env: ['BROWSERSTACK_USERNAME=deeplearnjs1', 'NIGHTLY=$_NIGHTLY']
   secretEnv: ['BROWSERSTACK_KEY']
 
 # Run C++ tests.
diff --git a/tfjs-backend-wasm/karma.conf.js b/tfjs-backend-wasm/karma.conf.js
index 796311cd15c..fb879c7ea15 100644
--- a/tfjs-backend-wasm/karma.conf.js
+++ b/tfjs-backend-wasm/karma.conf.js
@@ -42,6 +42,34 @@ const karmaTypescriptConfig = {
   include: ['src/', 'wasm-out/']
 };
 
+const devConfig = {
+  frameworks: ['jasmine', 'karma-typescript'],
+  files: [
+    {pattern: './node_modules/@babel/polyfill/dist/polyfill.js'},
+    // Setup the environment for the tests.
+    'src/setup_test.ts',
+    // Serve the wasm file as a static resource.
+    {pattern: 'wasm-out/**/*.wasm', included: false},
+    // Import the generated js library from emscripten.
+    {pattern: 'wasm-out/**/*.js'},
+    // Import the rest of the sources.
+    {pattern: 'src/**/*.ts'},
+  ],
+  exclude: ['src/test_node.ts'],
+  preprocessors: {
+    'wasm-out/**/*.js': ['karma-typescript'],
+    '**/*.ts': ['karma-typescript']
+  },
+  karmaTypescriptConfig,
+  reporters: ['dots', 'karma-typescript']
+};
+
+const browserstackConfig = {
+  ...devConfig,
+  hostname: 'bs-local.com',
+  singleRun: true
+};
+
 module.exports = function(config) {
   const args = [];
   if (config.grep) {
@@ -50,45 +78,35 @@ module.exports = function(config) {
   if (config.flags) {
     args.push('--flags', config.flags);
   }
+
+  let extraConfig = null;
+
+  if (config.browserstack) {
+    extraConfig = browserstackConfig;
+  } else {
+    extraConfig = devConfig;
+  }
+
   config.set({
+    ...extraConfig,
     basePath: '',
-    frameworks: ['jasmine', 'karma-typescript'],
-    files: [
-      {pattern: './node_modules/@babel/polyfill/dist/polyfill.js'},
-      // Setup the environment for the tests.
-      'src/setup_test.ts',
-      // Serve the wasm file as a static resource.
-      {pattern: 'wasm-out/**/*.wasm', included: false},
-      // Import the generated js library from emscripten.
-      {pattern: 'wasm-out/**/*.js'},
-      // Import the rest of the sources.
-      {pattern: 'src/**/*.ts'},
-    ],
-    exclude: ['src/test_node.ts'],
-    preprocessors: {
-      'wasm-out/**/*.js': ['karma-typescript'],
-      '**/*.ts': ['karma-typescript']
-    },
-    karmaTypescriptConfig,
     // Redirect the request for the wasm file so karma can find it.
     proxies: {
       '/base/node_modules/karma-typescript/dist/client/tfjs-backend-wasm.wasm':
           '/base/wasm-out/tfjs-backend-wasm.wasm',
     },
-    reporters: ['dots', 'karma-typescript'],
-    port: 9876,
-    colors: true,
-    autoWatch: true,
     browsers: ['Chrome'],
     browserStack: {
       username: process.env.BROWSERSTACK_USERNAME,
-      accessKey: process.env.BROWSERSTACK_KEY
+      accessKey: process.env.BROWSERSTACK_KEY,
+      timeout: 1800
     },
-    singleRun: false,
-    captureTimeout: 120000,
+    captureTimeout: 3e5,
     reportSlowerThan: 500,
-    browserNoActivityTimeout: 180000,
-    client: {jasmine: {random: false}, args: args},
+    browserNoActivityTimeout: 3e5,
+    browserDisconnectTimeout: 3e5,
+    browserDisconnectTolerance: 0,
+    browserSocketTimeout: 1.2e5,
     customLaunchers: {
       // For browserstack configs see:
       // https://www.browserstack.com/automate/node
@@ -98,7 +116,45 @@ module.exports = function(config) {
         browser_version: 'latest',
         os: 'OS X',
         os_version: 'High Sierra'
+      },
+      bs_firefox_mac: {
+        base: 'BrowserStack',
+        browser: 'firefox',
+        browser_version: 'latest',
+        os: 'OS X',
+        os_version: 'High Sierra'
+      },
+      bs_safari_mac: {
+        base: 'BrowserStack',
+        browser: 'safari',
+        browser_version: 'latest',
+        os: 'OS X',
+        os_version: 'High Sierra'
+      },
+      bs_ios_11: {
+        base: 'BrowserStack',
+        device: 'iPhone X',
+        os: 'iOS',
+        os_version: '11.0',
+        real_mobile: true
+      },
+      bs_android_9: {
+        base: 'BrowserStack',
+        device: 'Google Pixel 3 XL',
+        os: 'android',
+        os_version: '9.0',
+        real_mobile: true
+      },
+      win_10_chrome: {
+        base: 'BrowserStack',
+        browser: 'chrome',
+        // Latest Chrome on Windows has WebGL problems:
+        // https://github.com/tensorflow/tfjs/issues/2272
+        browser_version: '77.0',
+        os: 'Windows',
+        os_version: '10'
       }
-    }
+    },
+    client: {jasmine: {random: false}, args: args},
   })
 }
diff --git a/tfjs-backend-wasm/package.json b/tfjs-backend-wasm/package.json
index 20bd899614f..92c253a7861 100644
--- a/tfjs-backend-wasm/package.json
+++ b/tfjs-backend-wasm/package.json
@@ -32,7 +32,7 @@
     "test-node": "ts-node --skip-ignore -P tsconfig.test.json src/test_node.ts",
     "test-bundle-size": "./scripts/test-bundle-size.js",
     "test-cc": "bazel test //src/cc:cc_tests --test_output=all",
-    "test-browser-ci": "karma start --singleRun --browsers=bs_chrome_mac"
+    "run-browserstack": "karma start --browserstack"
   },
   "browser": {
     "fs": false,
diff --git a/tfjs-backend-wasm/scripts/test-ci.sh b/tfjs-backend-wasm/scripts/test-ci.sh
index 873c7aa2fee..7ad2d412d3e 100755
--- a/tfjs-backend-wasm/scripts/test-ci.sh
+++ b/tfjs-backend-wasm/scripts/test-ci.sh
@@ -11,4 +11,12 @@ set -e
 
 # Regular testing.
 yarn test-node
-yarn test-browser-ci
+
+if [ "$NIGHTLY" = true ]; then
+  yarn run-browserstack --browsers=bs_safari_mac
+  yarn run-browserstack --browsers=bs_firefox_mac,bs_chrome_mac
+  yarn run-browserstack --browsers=win_10_chrome,bs_android_9
+  yarn run-browserstack --browsers=bs_ios_11
+else
+  yarn run-browserstack --browsers=bs_chrome_mac
+fi
diff --git a/tfjs-backend-wasm/src/setup_test.ts b/tfjs-backend-wasm/src/setup_test.ts
index 9f84a680730..9f05e017c38 100644
--- a/tfjs-backend-wasm/src/setup_test.ts
+++ b/tfjs-backend-wasm/src/setup_test.ts
@@ -224,7 +224,7 @@ const TEST_FILTERS: TestFilter[] = [
   {include: 'oneHot'},
   {include: 'split'},
   {include: 'pad ', excludes: ['complex', 'zerosLike']},
-  {include: 'clip', excludes: ['gradient']},
+  {include: 'clip', excludes: ['gradient', 'propagates NaNs']},
   {include: 'addN'},
   {include: 'nonMaxSuppression'},
   {include: 'argmax', excludes: ['gradient']},