App-ads.txt (Authorized Digital Sellers for Mobile Apps) is a simple yet powerful tool that helps app developers and publishers protect their advertising inventory from fraud. By publishing a small text file on their developer website, app owners can publicly declare which advertising platforms are authorized to sell their ad space.
This initiative, developed by the IAB Tech Lab, extends the benefits of ads.txt from web advertising into the world of mobile apps and connected TV (OTT). It creates a transparent marketplace where advertisers can easily verify legitimate sellers before purchasing inventory.
App-ads.txt is a publicly available text file that confirms which ad networks and supply-side platforms (SSPs) are allowed to sell an app’s advertising space. Each record inside the file represents an authorized partner that has direct or reseller permission to sell the developer’s inventory.
In simple terms, it acts like an official guest list for your ad space — only vendors on the list can sell your impressions. This prevents fraudsters from pretending to represent your app or reselling fake inventory.
This process ensures that only legitimate partners can transact ad impressions for the app.
google.com, pub-1234567890123456, DIRECT, f08c47fec0942fa0
Explanation
The digital advertising ecosystem relies on automated bidding and exchanges. Without strong verification, it becomes vulnerable to fraud, spoofing, and unauthorized reselling. App-ads.txt solves these problems by making the relationship between sellers and ad networks transparent.
Key problems it prevents
1. Stronger Security and Fraud Prevention
By verifying authorized sellers, App-ads.txt blocks fake inventory and keeps ad dollars safe from fraud.
2. Greater Transparency and Trust
Advertisers can easily confirm who is permitted to sell an app’s ad space. Publishers gain credibility by making this information public.
3. Brand Safety for Advertisers
Advertisers ensure that their ads appear only on verified, authentic apps, protecting their brand reputation and targeting accuracy.
4. Increased Publisher Revenue
When only authorized partners can sell inventory, publishers capture more of their rightful ad revenue instead of losing it to fraudulent resellers.
Once live, buyers can instantly verify your authorized ad partners, ensuring your app’s ad inventory is secure and trustworthy.
It stands for Authorized Digital Sellers for Mobile Apps. It is the mobile version of ads.txt used for websites.
Yes. The file must be hosted on your developer website and linked from your app store listing so buyers can locate and verify it.
While not legally required, it has become an industry standard. Major platforms like Google and Apple encourage or require it for better ad verification.
Yes, as long as you trust them and they have legitimate access to your inventory. Mark them as RESELLER instead of DIRECT.
You should update it whenever you add, remove, or change ad partners. Keeping it current ensures transparency and maximizes revenue protection.
Without it, your app is more vulnerable to fraud, spoofing, and lost revenue. Advertisers may also avoid bidding on your inventory due to lack of verification.