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.

ifoodie.tw achieves the best ad optimization: its app-ads.txt has no errors and matches what its 6 ad networks expect (100% of 8 lines).

Checked 20 Oct 2026. 58 lines, 40 unique records, 9 duplicates, 0 invalid lines, 7 ad networks detected.

Google AdMob — accounts pub-9874927516416876, pub-3284479043848404, pub-3940256099942544: 3 lines in the file
Index Exchange — account 197455: 1 line in the file
PubMatic — account 159855: 1 line in the file
OpenX — account 556893927: 1 line in the file
Smaato — accounts 1100051335, 1100050217, 1100004890: 3 lines in the file
Magnite (Rubicon) — account 22884: 1 line in the file
Yango Ads — partner (reseller) lines only: 11 lines in the file, 400 expected lines missing

Yes — https://ifoodie.tw/app-ads.txt has 58 lines (checked 20 Oct 2026).

Its app-ads.txt lists Google AdMob, Index Exchange, PubMatic, OpenX, Smaato, Magnite (Rubicon), Yango Ads.

ifoodie.tw achieves the best ad optimization: its app-ads.txt has no errors and matches what its 6 ad networks expect (100% of 8 lines).