AdMob Banner Test IDs: Select the Correct Format and Never Click Live Ads

Select the banner format

The Android legacy test-ad guide checked on 22 September 2026 lists:

These are ad-unit IDs, not the sample app ID used during SDK setup. Follow the test guide for the SDK family and platform you actually use; do not assume an Android legacy example is the iOS identifier.

Test layout and lifecycle, not only loading

Verify that the banner container has the intended width, respects safe areas and does not cover controls. Exercise rotation, navigation away and back, backgrounding and destruction. Confirm that stale views and listeners are cleaned up.

For adaptive banners, compute the usable width from the actual container. A full-display width can be wrong inside a split screen or inset layout.

Read failures in context

Record the error code, message, response information and SDK version. Separate initialization failures, invalid configuration, network problems and availability. Repeated immediate retries can obscure the original issue and create unnecessary requests.

A demo ad loading successfully confirms part of the integration. It does not prove production eligibility, account readiness or mediation performance.

Check the release boundary

Before publication, replace demo placement IDs with the intended production IDs and verify the app-ID pairing. Keep test-device configuration available for safe maintenance testing according to the SDK guidance.

APKLint can inspect selected advertising declarations in an APK, but it cannot mark a physical device as a test device or inspect your account's serving state.

Use the official test-ad reference as the source of the identifiers. Keep the format, platform, SDK family and environment visible in your configuration names so a future developer does not replace a test banner with a live unit by accident.