Verifying app-ads.txt for AdMob, step by step

If your app shows ads through AdMob, sooner or later you will see a warning that your app-ads.txt file could not be verified. Ads still serve, but unverified inventory can earn less, and the warning does not go away by itself.

app-ads.txt is a small text file that says which ad networks are allowed to sell your app's inventory. AdMob finds it through a chain:

1. The developer website field on your Google Play listing
2. The root of that website
3. A file named app-ads.txt at that root

All three have to line up.

Step 1: Put the file at the root of your site

Create app-ads.txt with the line AdMob gives you (AdMob > Apps > View all apps > app-ads.txt). It looks like this:

google.com, pub-0000000000000000, DIRECT, f08c47fec0942fa0

With Astro, Next.js or most static hosts, dropping the file in the public folder is enough. Open https://your-domain/app-ads.txt in a browser and check that it loads as plain text, with no redirect and no HTML around it.

Step 2: Point the Play listing at that domain

In the Play Console, go to Store presence > Store settings > Store listing contact details and set the website to the same domain, for example https://kklabs.vercel.app. Save and publish the change.

This step is the one most people miss. AdMob does not search for your file; it only follows the website on the listing.

Step 3: Ask AdMob to check again

Back in AdMob, open the app-ads.txt tab and choose Check for updates. The crawler can take anywhere from a few hours to a day to pick up the change.

Common reasons it still fails

• The file is on www. but the listing points to the bare domain, or the other way round
• The host serves the file with a redirect
• The publisher ID has a typo or a missing pub- prefix
• The listing change was saved but not published

One file can cover every app you publish under the same developer account, which is why it lives on the studio site rather than on each app's page.