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.

welt.de app-ads.txt check

welt.de achieves the best ad optimization: its app-ads.txt has no errors and matches what its 10 ad networks expect (100% of 24 lines).

Checked 20 Oct 2026. 200 lines, 169 unique records, 3 duplicates, 0 invalid lines, 12 ad networks detected.

Ad networks in welt.de/app-ads.txt

Xandr (Microsoft) — account 7823: 1 line in the file
Google AdMob — account pub-5786819153313314: 1 line in the file
Amazon Publisher Services — account 3135: 1 line in the file
OpenX — accounts 539948074, 540038340, 560867217: 3 lines in the file
PubMatic — accounts 157222, 156678, 161921 and 4 more: 7 lines in the file
Index Exchange — accounts 188480, 188479, 214561 and 1 more: 4 lines in the file
Magnite (Rubicon) — accounts 19248, 10113, 22426: 3 lines in the file
TripleLift — accounts 5791-EB, 5791: 2 lines in the file
Criteo — account B-048188: 1 line in the file
Meta Audience Network — accounts 340030725, 640581217, com.netbiscuits.bild.android and 1 more: 4 lines in the file
Mintegral — partner (reseller) lines only: 21 lines in the file, 400 expected lines missing
Yango Ads — partner (reseller) lines only: 23 lines in the file, 400 expected lines missing

Corrected file: welt.de app-ads.txt (fixed).

FAQ

Does welt.de have an app-ads.txt?

Yes — https://welt.de/app-ads.txt has 200 lines (checked 20 Oct 2026).

Which ad networks does welt.de work with?

Its app-ads.txt lists Xandr (Microsoft), Google AdMob, Amazon Publisher Services, OpenX, PubMatic, Index Exchange, Magnite (Rubicon), TripleLift, Criteo, Meta Audience Network, Mintegral, Yango Ads.

Is the app-ads.txt of welt.de correct?