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.

ifthendev.com achieves the best ad optimization: its app-ads.txt has no errors and matches what its ad network expects (100% of 36 lines).

Checked 20 Oct 2026. 36 lines, 36 unique records, 0 duplicates, 0 invalid lines, 8 ad networks detected.

AppLovin — account 81106c6f74e2e4b141f09786f22a58c3: 36 lines in the file
Mintegral — partner (reseller) lines only: 12 lines in the file, 400 expected lines missing
Liftoff Monetize (Vungle) — partner (reseller) lines only: 13 lines in the file, 377 expected lines missing
Chartboost — partner (reseller) lines only: 11 lines in the file, 400 expected lines missing
DT Exchange (Fyber) — partner (reseller) lines only: 11 lines in the file, 400 expected lines missing
Yango Ads — partner (reseller) lines only: 35 lines in the file, 400 expected lines missing
Verve (PubNative) — partner (reseller) lines only: 10 lines in the file, 400 expected lines missing
Bidmachine — partner (reseller) lines only: 12 lines in the file, 400 expected lines missing

Yes — https://ifthendev.com/app-ads.txt has 36 lines (checked 20 Oct 2026).

Its app-ads.txt lists AppLovin, Mintegral, Liftoff Monetize (Vungle), Chartboost, DT Exchange (Fyber), Yango Ads, Verve (PubNative), Bidmachine.

ifthendev.com achieves the best ad optimization: its app-ads.txt has no errors and matches what its ad network expects (100% of 36 lines).