App Cannot Access API on LambdaTest Real Device and Emulator(But Works in Browser)

TestMu AI Support
1

Hi,

We are experiencing an issue while testing our mobile application on LambdaTest.

  • The base URL is only accessible via VPN.

  • Using LambdaTest Tunnel, we can access the domain successfully from the device browser (both real devices and emulators).

  • However, when the application tries to access the same URL, it fails and the app gets stuck on the splash screen.

Additional details:

  • The same request works correctly via Postman (with VPN).

  • The same URL is accessible via the browser on LambdaTest devices.

  • The issue only occurs when the request is made from within the app on LambdaTest.

Could you please help us understand why the application cannot access the API while browser access works correctly?

2

This is a classic cloud-device + VPN tunneling edge case. The fact that: Works in browser on LambdaTest Works via Postman (with VPN) Fails inside your mobile app confirms that the tunnel is partially working, but your app is hitting something the browser is not.

Browser traffic is not same as App traffic inside LambdaTest

Even though both run on the same device, they can differ in:

  • DNS resolution

  • SSL handling

  • Network security policies

  • Proxy/tunnel routing behavior

3

Thanks for the explanation, but there is an update on our side.

The API is no longer VPN-restricted. It’s now accessible only from our whitelisted IP, and the app works fine on real devices.

However, on LambdaTest, the app still cannot reach the API (with or without tunnel), while the browser can.

Also, we’ve tested other apps before with VPN/tunnel setups on LambdaTest and didn’t face this issue. This is the first time.

So it feels like the app traffic might not be going through the tunnel and is instead coming from LambdaTest IPs.

Did you ever see something like this before?