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.

ct.de app-ads.txt check

ct.de achieves the best ad optimization: its app-ads.txt has no errors and matches what its 8 ad networks expect (100% of 16 lines).

Checked 20 Oct 2026. 421 lines, 276 unique records, 59 duplicates, 0 invalid lines, 19 ad networks detected.

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

Google AdMob — accounts pub-5312301662616820, pub-5121690421337506: 2 lines in the file
Xandr (Microsoft) — accounts 10053, 15027: 2 lines in the file
Index Exchange — accounts 188815, 188816, 183592: 3 lines in the file
OpenX — account 540717805: 1 line in the file
PubMatic — accounts 157767, 158983, 157743: 3 lines in the file
Magnite (Rubicon) — accounts 21772, 21770, 17280: 3 lines in the file
Sovrn — account 397546: 1 line in the file
TripleLift — accounts 6452, 6452-EB: 2 lines in the file
Mintegral — partner (reseller) lines only: 29 lines in the file, 400 expected lines missing
Liftoff Monetize (Vungle) — partner (reseller) lines only: 12 lines in the file, 378 expected lines missing
Chartboost — partner (reseller) lines only: 18 lines in the file, 400 expected lines missing
DT Exchange (Fyber) — partner (reseller) lines only: 14 lines in the file, 400 expected lines missing
VK Ads (myTarget) — partner (reseller) lines only: 12 lines in the file, 132 expected lines missing
BIGO Ads — partner (reseller) lines only: 29 lines in the file, 400 expected lines missing
Yango Ads — partner (reseller) lines only: 56 lines in the file, 400 expected lines missing
DSP Exchange — partner (reseller) lines only: 34 lines in the file, 400 expected lines missing
Maticoo (zMaticoo) — partner (reseller) lines only: 21 lines in the file, 400 expected lines missing
Verve (PubNative) — partner (reseller) lines only: 16 lines in the file, 400 expected lines missing
Bidmachine — partner (reseller) lines only: 51 lines in the file, 400 expected lines missing

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

FAQ

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

Yes — https://ct.de/app-ads.txt has 421 lines (checked 20 Oct 2026).

Which ad networks does ct.de work with?

Its app-ads.txt lists Google AdMob, Xandr (Microsoft), Index Exchange, OpenX, PubMatic, Magnite (Rubicon), Sovrn, TripleLift, Mintegral, Liftoff Monetize (Vungle), Chartboost, DT Exchange (Fyber) and 7 more.

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