An IAB Tech Lab standard that lets app publishers declare which ad networks are authorized to sell their inventory.

Where do I put the app-ads.txt file?

At the root of the developer website listed in your App Store / Google Play page, e.g. https://studio.com/app-ads.txt.

What is a Certification Authority ID?

An optional TAG-ID of the ad system, the 4th field of an app-ads.txt record.

prezzibenzina.it achieves the best ad optimization: its app-ads.txt has no errors and matches what its 6 ad networks expect (100% of 9 lines).

Checked 20 Oct 2026. 21 lines, 14 unique records, 0 duplicates, 0 invalid lines, 6 ad networks detected.

Google AdMob — accounts pub-7498176507529523, pub-8369562491381623, pub-5601224529449842 and 2 more: 5 lines in the file
PubMatic — accounts 106059, 157360: 2 lines in the file
Magnite (Rubicon) — accounts 12940, 19906: 2 lines in the file
OpenX — account 539927273: 1 line in the file
Index Exchange — accounts 188054, 188925: 2 lines in the file
Xandr (Microsoft) — account 9744: 1 line in the file

Yes — https://prezzibenzina.it/app-ads.txt has 21 lines (checked 20 Oct 2026).

Its app-ads.txt lists Google AdMob, PubMatic, Magnite (Rubicon), OpenX, Index Exchange, Xandr (Microsoft).

prezzibenzina.it achieves the best ad optimization: its app-ads.txt has no errors and matches what its 6 ad networks expect (100% of 9 lines).