diff --git a/tfjs-converter/cloudbuild.yml b/tfjs-converter/cloudbuild.yml
index 8197674c864..21291d8286f 100644
--- a/tfjs-converter/cloudbuild.yml
+++ b/tfjs-converter/cloudbuild.yml
@@ -6,7 +6,7 @@ steps:
   id: 'yarn-common'
   args: ['install']
 
-# Install converter dependencies
+# Install converter dependencies.
 - name: 'node:10'
   dir: 'tfjs-converter'
   entrypoint: 'yarn'
@@ -14,15 +14,38 @@ steps:
   args: ['install']
   waitFor: ['yarn-common']
 
-# Run browser tests.
+# Run lint.
 - name: 'node:10'
   dir: 'tfjs-converter'
   entrypoint: 'yarn'
-  id: 'test-browser'
-  args: ['test-ci']
+  id: 'lint'
+  args: ['lint']
+  waitFor: ['yarn']
+
+# Generate json file.
+- name: 'node:10'
+  dir: 'tfjs-converter'
+  entrypoint: 'yarn'
+  id: 'gen-json'
+  args: ['gen-json', '--test']
   waitFor: ['yarn']
-  env: ['BROWSERSTACK_USERNAME=deeplearnjs1', 'NIGHTLY=$_NIGHTLY']
-  secretEnv: ['BROWSERSTACK_KEY']
+
+# Build the project.
+- name: 'node:10'
+  dir: 'tfjs-converter'
+  entrypoint: 'yarn'
+  id: 'build'
+  args: ['build']
+  waitFor: ['gen-json']
+
+# Run javascript tests.
+- name: 'node:10'
+  dir: 'tfjs-converter'
+  entrypoint: 'yarn'
+  id: 'test-js'
+  args: ['test-ci']
+  waitFor: ['build']
+  env: ['NIGHTLY=$_NIGHTLY']
 
 # Run python tests.
 - name: 'gcr.io/google-appengine/python'
@@ -50,10 +73,6 @@ steps:
   args: ['test-snippets']
   waitFor: ['yarn']
 
-secrets:
-- kmsKeyName: projects/learnjs-174218/locations/global/keyRings/tfjs/cryptoKeys/enc
-  secretEnv:
-    BROWSERSTACK_KEY: CiQAkwyoIW0LcnxymzotLwaH4udVTQFBEN4AEA5CA+a3+yflL2ASPQAD8BdZnGARf78MhH5T9rQqyz9HNODwVjVIj64CTkFlUCGrP1B2HX9LXHWHLmtKutEGTeFFX9XhuBzNExA=
 timeout: 1800s
 logsBucket: 'gs://tfjs-build-logs'
 substitutions:
diff --git a/tfjs-converter/package.json b/tfjs-converter/package.json
index 15f24b24a76..582185c261b 100644
--- a/tfjs-converter/package.json
+++ b/tfjs-converter/package.json
@@ -58,10 +58,9 @@
     "build-npm": "./scripts/build-npm.sh",
     "link-local": "yalc link",
     "publish-local": "yarn build-npm && yalc push",
-    "test": "yarn gen-json --test && karma start",
-    "test-ci": "yarn gen-json --test && yarn build && yarn lint && yarn run-browserstack",
+    "test": "yarn gen-json --test && ts-node run_tests.ts",
+    "test-ci": "ts-node run_tests.ts",
     "test-snippets": "ts-node ./scripts/test_snippets.ts",
-    "run-browserstack": "karma start --singleRun --browsers='bs_firefox_mac,bs_chrome_mac' --reporters='dots,karma-typescript,BrowserStack'",
     "lint": "tslint -p . -t verbose",
     "make-version": "sh -c ./scripts/make-version",
     "gen-doc": "ts-node ./scripts/gen_doc.ts",
diff --git a/tfjs-converter/run_tests.ts b/tfjs-converter/run_tests.ts
new file mode 100644
index 00000000000..2fdce3c4f78
--- /dev/null
+++ b/tfjs-converter/run_tests.ts
@@ -0,0 +1,38 @@
+/**
+ * @license
+ * Copyright 2020 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * =============================================================================
+ */
+
+// tslint:disable-next-line:no-imports-from-dist
+import * as jasmine_util from '@tensorflow/tfjs-core/dist/jasmine_util';
+
+// tslint:disable-next-line:no-require-imports
+const jasmineCtor = require('jasmine');
+// tslint:disable-next-line:no-require-imports
+
+Error.stackTraceLimit = Infinity;
+
+process.on('unhandledRejection', e => {
+  throw e;
+});
+
+jasmine_util.setTestEnvs(
+    [{name: 'test-converter', backendName: 'cpu', flags: {}}]);
+
+const unitTests = 'src/**/*_test.ts';
+
+const runner = new jasmineCtor();
+runner.loadConfig({spec_files: [unitTests], random: false});
+runner.execute();
diff --git a/tfjs-converter/src/operations/executors/dynamic_executor_test.ts b/tfjs-converter/src/operations/executors/dynamic_executor_test.ts
index 1f4ddd056f6..4663423178a 100644
--- a/tfjs-converter/src/operations/executors/dynamic_executor_test.ts
+++ b/tfjs-converter/src/operations/executors/dynamic_executor_test.ts
@@ -55,7 +55,7 @@ describe('dynamic', () => {
         const input3 = [tfc.tensor1d([1])];
         const input4 = [tfc.tensor1d([1])];
         const input5 = [tfc.tensor1d([1])];
-        spyOn(tfc.image, 'nonMaxSuppressionAsync').and.callThrough();
+        spyOn(tfc.image, 'nonMaxSuppressionAsync');
         const result =
             executeOp(node, {input1, input2, input3, input4, input5}, context);
         expect(tfc.image.nonMaxSuppressionAsync)
@@ -88,7 +88,7 @@ describe('dynamic', () => {
         const input3 = [tfc.tensor1d([1])];
         const input4 = [tfc.tensor1d([1])];
         const input5 = [tfc.tensor1d([1])];
-        spyOn(tfc.image, 'nonMaxSuppressionAsync').and.callThrough();
+        spyOn(tfc.image, 'nonMaxSuppressionAsync');
         const result =
             executeOp(node, {input1, input2, input3, input4, input5}, context);
         expect(tfc.image.nonMaxSuppressionAsync)
@@ -125,7 +125,7 @@ describe('dynamic', () => {
         const input4 = [tfc.tensor1d([1])];
         const input5 = [tfc.tensor1d([1])];
         const input6 = [tfc.tensor1d([1])];
-        spyOn(tfc.image, 'nonMaxSuppressionWithScoreAsync').and.callThrough();
+        spyOn(tfc.image, 'nonMaxSuppressionWithScoreAsync').and.returnValue({});
         const result = executeOp(
             node, {input1, input2, input3, input4, input5, input6}, context);
         expect(tfc.image.nonMaxSuppressionWithScoreAsync)
@@ -153,7 +153,7 @@ describe('dynamic', () => {
         node.op = 'Where';
         node.inputParams = {'condition': createTensorAttr(0)};
         const input1 = [tfc.scalar(1)];
-        spyOn(tfc, 'whereAsync').and.callThrough();
+        spyOn(tfc, 'whereAsync');
 
         const result = executeOp(node, {input1}, context);
         expect((tfc.whereAsync as jasmine.Spy).calls.mostRecent().args[0].dtype)
@@ -180,7 +180,7 @@ describe('dynamic', () => {
         node.inputParams = {'x': createTensorAttr(0), 'y': createTensorAttr(1)};
         const input1 = [tfc.scalar(1)];
         const input2 = [tfc.scalar(1)];
-        spyOn(tfc, 'setdiff1dAsync').and.callThrough();
+        spyOn(tfc, 'setdiff1dAsync');
 
         const result = executeOp(node, {input1, input2}, context);
         expect(tfc.setdiff1dAsync).toHaveBeenCalledWith(input1[0], input2[0]);