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.

25ans.jp app-ads.txt check

25ans.jp achieves the best ad optimization: its app-ads.txt has no errors and matches what its 9 ad networks expect (100% of 17 lines).

Checked 20 Oct 2026. 68 lines, 66 unique records, 0 duplicates, 0 invalid lines, 9 ad networks detected.

Ad networks in 25ans.jp/app-ads.txt

Amazon Publisher Services — accounts 3049, 3985: 2 lines in the file
Xandr (Microsoft) — account 7287: 1 line in the file
Google AdMob — account pub-1301581561755234: 1 line in the file
Index Exchange — accounts 184046, 187614, 194269: 3 lines in the file
OpenX — accounts 539330234, 557916699: 2 lines in the file
PubMatic — accounts 157075, 156694, 167956: 3 lines in the file
Magnite (Rubicon) — accounts 15896, 11636, 14476: 3 lines in the file
TripleLift — account 967: 1 line in the file
Yahoo — account 59985: 1 line in the file

Corrected file: 25ans.jp app-ads.txt (fixed).

FAQ

Does 25ans.jp have an app-ads.txt?

Yes — https://25ans.jp/app-ads.txt has 68 lines (checked 20 Oct 2026).

Which ad networks does 25ans.jp work with?

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

Is the app-ads.txt of 25ans.jp correct?