Ad inspector (Beta)

Ad inspector is an in-app overlay that enables authorized devices to perform realtime analysis of test ad requests directly within a mobile app. It is included with the Google Mobile Ads SDK version 20.0.0 and higher, and can be enabled with no coding required.

Using ad inspector, you can:

  • Inspect your ad units
  • Check whether your ads are filling as expected
  • Identify errors and view details about how to resolve them
  • View the mediation waterfall details for each ad network per request
  • Test individual third-party waterfall ad sources
  • Verify that you've correctly configured each ad unit for mediation

This guide demonstrates how to launch and use the different features in ad inspector.


In order to use ad inspector, you need to:

  • Complete the Get Started guide.
  • Google Mobile Ads SDK version 20.0.0 or higher.

Launching ad inspector

Ad inspector can be launched from anywhere in your app. There are two different ways to launch ad inspector.

  1. Use the gesture selected in the AdMob UI when registering a test device.

  2. Programmatically using the provided API.

Launching using gestures

No changes are needed to your app to launch ad inspector with a gesture. Simply perform the gesture (double flick or shake) that you configured in AdMob for that test device. Learn more.

Launching programmatically

Ad inspector can also be launched programmatically:

MobileAds.openAdInspector(context, new OnAdInspectorClosedListener() {
  public void onAdInspectorClosed(@Nullable AdInspectorError error) {
    // Error will be non-null if ad inspector closed due to an error.

This API works for test devices registered programmatically or in the AdMob UI.

Viewing recent ad request results by ad unit

Once launched, the main screen of ad inspector appears, containing a list of all ad units in the AdMob UI associated with your AdMob app ID that have mediation or bidding configurations:

app id screen

Ad units are ordered chronologically with most recently completed requests first. As shown above, known ad units with no requests completed are dimmed.

Viewing ad request details for an ad unit

Tap an ad unit to view its SDK request log, which details the mediation waterfall until the ad was filled (or the waterfall ended without a fill) for the latest ad requests.

Each request can be expanded using the disclosure indicator to show the results of the mediation waterfall for that request, with any error and latency that was applicable for that request.

request log

Performing a single ad source test

Ad inspector has a feature to restrict ad requests in your app to only serve ads from a single third-party ad source. This lets you verify that you've correctly implemented the third-party mediation adapter and that the ad source is serving as expected, regardless of where that ad source is placed in the mediation waterfall.

To enable this feature, toggle the Single ad source test switch at the bottom of the ad units list screen. This displays the following ad source selection dialog:

ad source 1 ad source 2 ad source 3

You can then select a single ad source to test. Once an ad source is selected, the following screen appears:

restart screen

The single ad source test setting applies to any future ad requests you make in the same session. However, it won't apply to any previously cached ads in that session that have not yet been shown. Force restarting your app is recommended when applying a single ad source test in order to invalidate any cached ads that could be served instead of your chosen ad source receiving a request.

After restarting your app, all ad unit placements will attempt to show an ad from the selected network only. Launching ad inspector when a single ad source test is active will show the active test ad source:

ad source 4

In a single ad source test, you can tap an ad unit to view its SDK request log. This lets you know whether the ad source filled the ad requests made after single ad source testing is enabled. If the ad source failed to load an ad, an error message appears describing the error.

If you've added multiple instances of the selected ad source to a mediation waterfall, you'll see each instance of the call to the ad source in the waterfall until the ad is either filled or the waterfall ended without a fill.

Stopping a single ad source test

To stop the test, toggle the switch to off:

stop test

A confirmation message then appears over the following restart screen:

restart screen

We recommend a force restart of your app after stopping the test in order to invalidate any cached ads for the ad source that was tested.