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.

subito.it achieves the best ad optimization: its app-ads.txt has no errors and matches what its 8 ad networks expect (100% of 14 lines).

Checked 21 Oct 2026. 26 lines, 25 unique records, 0 duplicates, 0 invalid lines, 8 ad networks detected.

Google AdMob — accounts pub-1864299690923038, pub-2936779777320639: 2 lines in the file
Xandr (Microsoft) — account 3296: 1 line in the file
Magnite (Rubicon) — accounts 23660, 22658: 2 lines in the file
Criteo — account B-059632: 1 line in the file
PubMatic — accounts 81997, 159696: 2 lines in the file
Index Exchange — accounts 195761, 192531, 190718: 3 lines in the file
OpenX — accounts 541153841, 541155774: 2 lines in the file
TripleLift — accounts 8578, 8578-EB: 2 lines in the file

Yes — https://subito.it/app-ads.txt has 26 lines (checked 21 Oct 2026).

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

subito.it achieves the best ad optimization: its app-ads.txt has no errors and matches what its 8 ad networks expect (100% of 14 lines).