diff --git a/js/web/script/test-runner-cli.ts b/js/web/script/test-runner-cli.ts
index 59bd0d5f6313a..ace64e9532b12 100644
--- a/js/web/script/test-runner-cli.ts
+++ b/js/web/script/test-runner-cli.ts
@@ -569,6 +569,9 @@ async function main() {
       if (webnn) {
         chromiumFlags.push('--enable-experimental-web-platform-features');
       }
+      if (process.argv.includes('--karma-debug')) {
+        karmaArgs.push('--log-level debug');
+      }
       karmaArgs.push(`--bundle-mode=${args.bundleMode}`);
       karmaArgs.push(...chromiumFlags.map(flag => `--chromium-flags=${flag}`));
       if (browser.startsWith('Edge')) {
diff --git a/tools/ci_build/github/azure-pipelines/templates/win-web-ci.yml b/tools/ci_build/github/azure-pipelines/templates/win-web-ci.yml
index b882d6fb167fd..9553bc1bc3547 100644
--- a/tools/ci_build/github/azure-pipelines/templates/win-web-ci.yml
+++ b/tools/ci_build/github/azure-pipelines/templates/win-web-ci.yml
@@ -153,31 +153,31 @@ jobs:
       errorActionPreference: stop
     displayName: 'Pack NPM packages'
   - script: |
-     npm test -- -e=chrome -b=webgl,wasm
+     npm test -- -e=chrome -b=webgl,wasm --karma-debug
     workingDirectory: '$(Build.SourcesDirectory)\js\web'
     displayName: 'Run ort-web tests (wasm,webgl backend)'
     condition: eq('${{ parameters.RunWebGpuTests }}', 'false')
   - script: |
-     npm test -- -e=chrome -b=webgl,wasm,webgpu $(webgpuCommandlineExtraFlags)
+     npm test -- -e=chrome -b=webgl,wasm,webgpu --karma-debug $(webgpuCommandlineExtraFlags)
     workingDirectory: '$(Build.SourcesDirectory)\js\web'
     displayName: 'Run ort-web tests (ALL backends)'
     condition: eq('${{ parameters.RunWebGpuTests }}', 'true')
   - script: |
-     npm test -- suite1 -e=chrome -b=webgpu --io-binding=gpu-tensor $(webgpuCommandlineExtraFlags)
+     npm test -- suite1 -e=chrome -b=webgpu --io-binding=gpu-tensor --karma-debug $(webgpuCommandlineExtraFlags)
     workingDirectory: '$(Build.SourcesDirectory)\js\web'
     displayName: 'Run ort-web tests (Suite1, webgpu, IO-binding=gpu-tensor)'
     condition: eq('${{ parameters.RunWebGpuTests }}', 'true')
   - script: |
-     npm test -- suite1 -e=chrome -b=webgpu --io-binding=gpu-location $(webgpuCommandlineExtraFlags)
+     npm test -- suite1 -e=chrome -b=webgpu --io-binding=gpu-location --karma-debug $(webgpuCommandlineExtraFlags)
     workingDirectory: '$(Build.SourcesDirectory)\js\web'
     displayName: 'Run ort-web tests (Suite1, webgpu, IO-binding=gpu-location)'
     condition: eq('${{ parameters.RunWebGpuTests }}', 'true')
   - script: |
-     npm test -- --webgl-texture-pack-mode -b=webgl -e=chrome
+     npm test -- --webgl-texture-pack-mode -b=webgl -e=chrome --karma-debug
     workingDirectory: '$(Build.SourcesDirectory)\js\web'
     displayName: 'Run ort-web tests - WebGL: packed mode'
   - script: |
-     npm test -- --wasm-enable-proxy -b=wasm -e=chrome
+     npm test -- --wasm-enable-proxy -b=wasm -e=chrome --karma-debug
     workingDirectory: '$(Build.SourcesDirectory)\js\web'
     displayName: 'Run ort-web tests - WebAssembly: proxy'
     condition: and(succeeded(), eq('${{ parameters.BuildConfig }}', 'Release'))