What is the ads.txt file?

The ads.txt (Authorized Digital Sellers) file is an initiative developed by the Interactive Advertising Bureau (IAB) to improve transparency and prevent unauthorized selling of ad inventory. It is a simple text file that publishers host on their web servers to publicly declare the companies authorized to sell their digital ad inventory.

In the ads.txt file, publishers list the authorized advertising partners, including ad networks, exchanges, and sales houses, along with their corresponding publisher account IDs. Advertisers and ad buyers can then verify this file to ensure that they are buying ad inventory from legitimate and authorized sellers.

By implementing ads.txt, publishers help combat ad fraud, domain spoofing, and unauthorized reselling of ad inventory, thereby creating a more transparent and trustworthy digital advertising ecosystem. Many advertising platforms and buyers require publishers to have a valid ads.txt file in place to ensure the legitimacy of the ad inventory they are purchasing.